A Brief Comparison of Federation and Empire

[A work in progress . . . last updated 11-06-05]


Quick Reference:  The War at a Glance

General Info: Number of Planets Territorial Size Total Population Planetary Defense 

Advantage:

Empire Empire Empire ????
Fleet Info: Fleet Ship Count Power Generation  Reactor Power
Advantage: Empire UFP UFP
Starship Defense: Shields Armor Cloaking Tech
Advantage: ???? UFP? Empire
Starship Offense: Beam Weapons Missile Weapons Weapons Ranges
Advantage: UFP UFP UFP
Starship Propulsion: Faster-than-Light Propulsion Slower-than-Light Propulsion
Advantage: ???? UFP
Various: Antigravity Technology Sensor Systems Fighter Craft
Advantage: Empire UFP ????
Various: Tactics and Strategy Ground Combat Tech Mines and Other Ordnance
Advantage: UFP ???? UFP
Other: Special (Unique) Tech Other Special Advantages Other Special Disadvantages General Observations


 

The Best of Both Worlds
Canon Data Only Unless Otherwise Noted
United Federation of Planets Galactic Empire
Planets

Advantage:
Empire

UFP is a
rounding
error
In "Metamorphosis"[TOS2], Kirk told Cochrane that "we're on a thousand planets and spreading out". Whether he referred to Earth colonies or total Federation colonies is uncertain.  In any case, by the later TNG era it was decided to make the UFP a sort of interstellar UN analog, and the number of Federation members was more or less fixed in the 150 range (as per Picard in First Contact).

In addition to member worlds there are also Federation protectorates, as we saw in Insurrection, and planets with "associate membership" status, as mentioned in "Attached"[TNG7]. Finally, there would be the apparently-large number of colonies.  However, the only total planetary count we have for certain is 1000 as of the 2260's, giving a rough minimum of 150 member worlds and 850+ colonies, with an unknown number of associates and protectorates.

About those colonies . . . if Kirk referred solely to Earth colonies, and every other Federation member world had at least 10, the total number of Federation colonies would be about 2500.   However, ten might be too many.   Colonization certainly didn't stop in the next hundred years, though . . . indeed, we know of colonies planted at the farthest reaches of Federation space in TNG ("BoBW1"), and there was apparently enough congestion to make terraforming desirable (though of course this was already the case with Weytahn in the early 2100s).   

Also from Enterprise, there is certainly no indication of any future Federation species having dozens upon dozens of planets in their personal grip, and Earth certainly doesn't.  This implies a TOS era (which should involve less than 150 member worlds) which has made significant gains in planet count over the past century.  Further, by volume alone, the TNG Federation should contain about 15,000 "Earth-type" planets, as per McCoy in "Balance of Terror" (more in the update here).   It is no great leap to grant that a third of these might've been colonized (not to mention those which are not Earth-like and/or could be colonized by other species).  

Final Tally: ~ 1,000 total systems, minimum. ~ 3,500, estimated.
Member Tally: ~150

Moff Tarkin says the Galactic Empire has a million systems in the ANH novelisation, and one may presume these are all inhabited, though this is not certain. In any case, at least several thousand solar systems are populated, since that is the number Dooku had under his thumb in Attack of the Clones, with another ten thousand ready to join him. It is not known what percentage of the Republic member worlds these systems represented, but Palpatine referred to the idea as the Republic being "split in two". This could refer to a numerical division of half-and-half, or may only represent a more general concept such as economics or population.

If we assume ~20,000 systems under the Separatists and a million worlds, though, we're only looking at 2% of the Republic in rebellion . . . that would be like losing one of the fifty states in the United States. Even if you picked the largest, most populous, or most prosperous of the 3,042 counties in the U.S., you still wouldn't realistically be able to say "split in two".

If it was a rough halving of the Republic, we could guess that the total number of full-membership Republic worlds was perhaps one hundred thousand, depending on how one wishes to define "several". The other 900,000 systems could either be uninhabited territorial holdings, or (more likely) colonies populated with some number of individuals.

Eyeball estimates based on a rough count of visible Senatorial pods suggests that there was only room for between 1,000 to 1,500 planetary senators (that's 30 observed levels at 36 pods per level for a total of 1080, plus room given for unobserved levels).  Certain large groups were also represented with a single seat, however, such as was the case with the Trade Federation's representative.

Coruscant is the most highly developed world by far, a planet almost completely covered by development, except for the seas. (This is apparently a unique state for a world in that era, as explained in the novelisation of TPM, p. 207.)

This planet, and the unknown number of others, represents a vast infrastructure, no matter the technology level. This is shown by the ability to construct huge battlestations such as the two Death Stars.

Final Tally: ~1,000,000 total systems
Member Tally: ~ 1,500 - 100,000 (rough estimate)

Territory Size

Advantage:
Empire

think USSR
and China
vs. US,
based on
diameter

at least 8 times
the volume
The Federation spans at least 8000 light-years in 2371, according to Picard in First Contact. Based on images of the Federation seen in "Conspiracy"[TNG1] and re-used in Keiko's classroom on DS9 (reproduced here), the Federation is a roughly oval, apparently-contiguous arrangement of planets. If it is 8,000 light years in maximum width, the length (from the outer galaxy toward the core) would be around 6,000 light years. Our galaxy's depth in this region is only about 1,000 light years. A rectangular box of such dimensions would thus have a volume of 48,000,000,000 cubic light-years.   (To get an idea of what our region of the galaxy looks like, take a look at this excellent page. Given the size of the Federation, there should be at least 200,000,000 stars within it.)
Bear in mind that this constitutes only a fraction of the stars charted by the Federation, though precisely what "charted" means is unclear. However, based on "The Corbomite Maneuver"[TOS1], "The Doomsday Machine"[TOS2], and "Transfigurations"[TNG3], star-charting usually involves going into an area and gathering data while they pass through. However, it is entirely possible that they have traded for star charts from others, or "charted" via subspace telescope. This may explain why that boob Kosinski said 11% of the galaxy had been charted during TNG season one, whereas by the very next year Wesley used the figure of 19%.  An 8,000 light-year wide circle going through the whole thickness of the galaxy would only account for 6% of the galaxy.

Final Tally: 8,000 x ~6,000 light-years
Given the million systems of the Empire, the size -- assuming it's just a million stars, and in a galaxy like ours -- could be up to about 2,000 light years (there are 250,000 stars within a 250 light-year radius of Earth, and 300 million stars within 5,000ly). To have a million potentially habitable systems, a likely minimum would be 12,000 light years. But, given Qui-Gon's statement that "most" of the stars of the SW galaxy have planetary systems, the "likely minimum" should actually be smaller. More information on this is available here.
Now, if Tarkin referred solely to populated systems, the size figure cannot be deduced by stellar population.  There are other canon indicators, however:
The ANH novelisation states that the Empire is a "tiny portion" of the galaxy, and a "tiny fraction of this section of one modest-sized galaxy". Qui-Gon suggests in TPM that not all the stars have been visited.  In the Local Group of 40 galaxies, even excluding anything below 10,000 light-years across, the average galaxy size of the remaining 13 is 36,500 light years (an estimate which holds for larger galaxies within 20 million light years).  Even if we assume a 73,000 light year galaxy (36,500 x 2) with low stellar density, a "tiny fraction of" a "section" of such a galaxy would have to be rather small.
(Note: Some argue that the use of phrases like "halfway across the galaxy" in TPM, "outer rim" in several movies, and Han's comment that he'd been from one side of the galaxy to the other implies that the Empire probably controls a huge fraction of the galaxy. However, this is highly unlikely, given what is known of the galaxy (and Han). For instance, the planet Kamino was referred to as being "beyond the outer rim", but the map in the Jedi library clearly zoomed in to an area very close to the core, meaning that "outer rim" cannot refer to the outermost rings of the galaxy. It should be noted that I am not being unfair here . . . I apply similar reasoning to Pike's comment to the Talosians about being from "the other end of this galaxy", and Picard's comments in "Conspiracy" that the Enterprise had been on the outer rim.)


Final Tally: ~ 10,000-12,000 light-years diameter (rough est.)
Population

Advantage:
Empire

100 to 1,
easy:
China, eat your
heart out
Riker seemed surprised by Data's statement (in "The Last Outpost"[TNG1]) that the T'kon Empire had a population numbering in the trillions, so one might guess at a Federation population of less than multiple trillions . . . though there could've been many reasons for Riker to seem surprised at such a high population for such an ancient regime.  Assuming a population of 5 billion per member world (Earth's current population), the Federation would have a population of 750 billion, not including associates, protectorates, or colonies.

Dialogue in "Statistical Probabilities"[DS9-6] suggests that a protracted war with the Dominion could, by one estimate, result in 900 billion Federation casualties and a Federation defeat. In this projection, five generations after the defeat, a rebellion would start on Earth, and within another generation the Dominion would be conquered, and a new Federation would be born.
The projection suggests that in spite of the unthinkable casualties, some if not all Alpha Quadrant races would survive quite well, even to the point of conquering the entire Dominion. 
So, a population under the boot of the Dominion and facing mass-produced troops manages to not only throw off their conquerors, but conquer them.  Given those conditions, requirements, and normal population growth rates, this would seem to suggest an absolute minimum Federation population in the mid-2370's on the order of two trillion, possibly more.

Militarily, we've never gotten a precise count of Starfleet numbers.  Late in the Dominion War, Captain Sisko referred to millions on the front lines ("The Dogs of War"[DS9-7]), and in "The Changing Face of Evil"[DS9-7] Legate Damar pointed out that seven million Cardassian soldiers had been killed in two years of war . . . a war which the Dominion was generally winning.  A similar number of Federation military casualties seems likely, suggesting fighting forces per regime on the order of tens of millions at minimum.  (The Dominion, of course, can grow its Jem'Hadar soldiers from infant to combat-capable teenager in a matter of two days ("The Abandoned"[DS9-3]), so determining the number of Jem'Hadar is haphazard at best.)

This follows, for the most part.  Wolf 359 cost the Federation some 11,000 lives and forty starships, suggesting an average crew count of 275.  If we take the ~10,000 starships of the Federation and assume an average crew count of 250, then we'd have 2.5 million people just aboard starships.  Such figures do not count the many bases and other facilities.  (For instance, "Field of Fire"[DS9-7] gives a Starfleet population of 900 on the station.)

Final Tally: ~ 2 trillion persons, rough minimum estimate

Coruscant alone could have a population of hundreds of billions quite easily, assuming Earth-city population density over the entire globe. Some suggest hundreds of trillions for Coruscant, but such figures fail to account for the huge industrial areas, as well as large areas (such as the one seen at the end of AoTC) which are evidently un- or lightly-populated, neglected ruins. In any case, Coruscant is the most developed world by far, as per the novel, and undoubtedly has what we 21st Century folk would consider a staggering population.
I would think it safe to assume a minimum Imperial population of at least several dozen trillion. If there were 5 billion people per Tarkin's "million systems", this would give a figure of 5,000,000,000,000,000 (five quadrillion), assuming those are all fully-populated member systems. If, on the other hand, there are only around 40,000 member systems (a rough figure estimating two times ten thousand plus "several thousand" from AoTC) with 5 billion persons per planet, the figure drops to 200 trillion. If we count only the number of Galactic Senate seats as the count of actual member worlds, then using 1,500 seats times 5 billion persons gives us a figure of 7.5 trillion. In any case, the Empire probably has, at ridiculous minimum, at least a dozen times the population of the Federation, and probably more like 500 times the Federation population.

Militarily, the Republic had few genuine soldiers.  At the start of the Clone War, just 200,000 clonetroopers were available as Army of the Republic, with a million more "well on the way" through the ten year growth cycle.  A Republic Navy was discussed at one point, though we have no indication of its size, or its roles beyond Jedi taxi service.

A generation later, the Empire had amassed a larger force.  Assuming a crew density similar to that of Federation starships, an ISD could easily have 10,000 crew aboard.  With 25,000 vessels of ISD-level equivalence, there could easily be 250,000,000 personnel in the Imperial navy, not counting those on stations and bases. 

Final Tally: ~ 200 trillion persons, rough minimum estimate

Planetary
Defense

Advantage:
??

UFP might have better systems,
but Imps are likely to have more
Planetary defense systems are referred to (TMP, "Homefront"[DS9-4]), but their nature is not delved into. Orbital defense outposts and drone ships (BoBW) are present in small numbers, though fleets also protect endangered planets ("Homefront" and "In the Pale Moonlight"[DS9-6]). Planetary shields are used on prison/asylum worlds ("Dagger of the Mind"[TOS1], "Whom Gods Destroy"[TOS3]), though their use on member worlds is unconfirmed. However,  Chakotay, in "Year of Hell, Pt. II"[VOY4], states that even less-sophisticated races ought to have planetary shields which could be reconfigured to stop the temporal weapon-ship, just as Voyager's shields had been.  The shielded surface research outpost in "Gambit"[TNG7] may have had planetary-scale shields, but this is uncertain. We do know that it had phasers and possibly photon torpedoes, which one would expect to be common for planetary defense.
An attack on Earth during the Dominion War managed to cause only light damage to San Francisco, though a fleet assault on Betazed, stated to have old and out-of-date planetary defenses, did capture that world.

 

System defense forces are a known quantity. Planetary shields might be  theoretically possible, though theatre shields are all that have ever been observed. We know from the ANH novel that Alderaan had some of the strongest defenses in the Empire, but we do not know what technologies are being referred to.
Based on what we do know, one would presume that a standard suite of planetary defenses would include:
1. theatre shields over major cities or special installations (as seen on Hoth in TESB)
2. ship-disabling ion cannons (also TESB)
3. defense fighters (even Naboo had some in TPM)
4. "local bulk-cruisers" (mentioned by Han in ANH, seemed to be slow police vessels) or other starships.
Ship
Count

Advantage:
Empire

Empire could have had way more, if they had bothered to build them
A minimum of 1000, based on dialog from Deep Space Nine, split into numbered Fleets, the highest known being the Tenth Fleet. At one point, the Seventh Fleet numbered 112 ships ("A Time To Stand"[DS9-6]). But, mere elements of the Second and Fifth combined into a 600 ship fleet to retake DS9, suggesting that some fleets had many more than 112 ships.
"Tacking Into The Wind"[DS9-7] claims that the Dominion War enemy forces (Dominion in the AQ, Cardassia, and the Breen) had 30,000 ships (the 1,500 Klingon warships that could be modified to resist the Breen weapon would be outnumbered 20 to 1). One would hope the Federation/Klingon/Romulan Alliance had at least half that many warships. The 30,000 figure correlates well with reaction to the Dominion loss of 2,800+ ships in "Sacrifice of Angels"[DS9-6], which might've constituted a loss of as much as half the Dominion fleet in the Alpha Quadrant at that point. A fair estimate would fall somewhere above 1000, but below 20,000.
The precise number of combat-capable starships compared to lesser vessels is unknown.  We know the Federation has a large number of Oberth class science ships and several emasculated Miranda class science/courier ships running around, but by far most of the starships we've seen (in or out of wartime) have been Excelsiors.

Starfleet fields an absurd number of ship classes. Refits are performed to bring ships closer to the latest technology, but old nacelles and other large-scale ship components are commonly retained in the 24th Century, implying that a vast array of warp coil shapes and sizes would need to be available for starships, either stored or specially made. Nevertheless, all the various hulls, nacelles, and internal components ought to constitute a significant drain on the logistical resources of Starfleet. 

(Note: A popular opposition argument is that Federation Tac-Fighters are included in ship counts. I have no idea where this notion comes from . . . the claim is not supported, suggested, or implied in the canon.   However, that use of the term "ship" does appear several times in Star Wars.)

Final Tally: ~ 10,000 (est.)

No direct canon statements are available, though there are indicators in the canon.  Han suggests that the entire fleet couldn't have destroyed Alderaan, as it would take a thousand ships massing more firepower than had ever existed to perform such a feat. (See the discussion of that scene on this page.)  The statement implies a huge fleet of ships with huge firepower, which would imply that the Imperial combat-capable starfleet is around 1000 ships or less.  
On the other hand, if Imperial ship count compared to member worlds is the same as for the Federation, there could be a few million ships. Further, an infrastructure that can build a Death Star should be able to field a hefty fleet. (Just by volume, the DS1 is worth over four billion Constitution Class ships.) 
Then again, they only had 27 starships at the Empire's most important tactical engagement (RoTJ) and their goal of stopping the Rebels from escaping would've been better served by more ships, so there's a great deal of uncertainty in play.  It's possible they were putting most of their eggs in one basket with the Death Stars.
An important note is that, unlike the UFP, the Empire has no known external threat forces or exploratory arms that would require huge fleets . . . their only threat is a rag-tag rebellion and memory of a civil war.  Their primary need for ships is to keep their worlds subjugated and in fear . . . which is precisely what the Death Star was designed to do.
Using Dodonna's statement that the DS1 had firepower greater than half the fleet, one can make an estimate which fits reasonably well within all of the above bounds.  It uses an ISD as a baseline, so the true individual ship count could swing either way depending on average firepower and numbers of each vessel type.
The vessel types which make up the Imperial starfleet have not been fleshed out in the slightest. The fleet is known to include different Imperator sub-types and a smaller number of Executors, and presumably older ship classes such as the Acclamators. "Local bulk-cruisers" are mentioned in a policing role and suggested to be slow compared to "big Corellian ships", presumably Star Destroyers.   Acclamators, at ~700 meters in length, are the smallest observed warships.

Final Tally: ~25,000 warships of ISD-level firepower equivalence
Reactor
Tech

Advantage:
UFP

more complex,
but more capable
Federation starships carry a single matter/antimatter reactor or "warp core", with fusion reactors for impulse flight and reserve batteries of unspecified technology for emergency power.   Certain late-model starships such as the Intrepid Class carry a dismantled warp core which can be built and installed in a short time in the event the primary core is damaged or ejected.   

Ship's power is distributed via plasma conduits, suggesting that energetic plasma powers most systems. A few systems, however -- most notably internal ship communications -- do use electronic circuitry at some point, as implied by Picard in "Symbiosis"[TNG1].

Though the non-canon Expanded Universe has graced us with such terms as "Solar Ionization" or "Hypermatter" reactors, the canon ANH novelisation puts the issue to rest when describing the Death Star's explosion: "Space filled temporarily with trillions of microscopic metal fragments, propelled past the retreating ships by the liberated energy of a small artificial sun." Somewhat strangely, the power of the Empire appears to be based on simple fusion.  (More on this can be found here.)
Even more strangely, their power distribution appears to be simple electricity via conductive wires, based on myriad references in the ANH novel, and Han's attempted "hot-wire" in RoTJ.   This may also explain the use of ion cannons.
Reactor
Power

Advantage:
UFP

more bang 
for the buck
At least five million gigawatts (5,000 terawatts) pour through a power conduit in "Revulsion"[VOY4]. Data, in "True Q"[TNG6], says the Enterprise (while orbiting a planet and not at alert status) is "presently generating twelve-point-seven-five billion gigawatts per . . . ", but is cut off.  More detail can be found here.  In any event, terawatt-class reactor energies are certain. Geordi comments in "The Masterpiece Society" that the reactor "kicks plasma up into the terawatt range", and in "Good Shepherd"[VOY6] Torres says "we need to route at least another five terawatts to the sensor array" . . . which implies that more than five terawatts were available for the long-range sensor boosting of the episode.  (And actually, the way she said it, as I've represented by italics above, suggests that some number of terawatts were already in use.)  

Final Tally: ~ 5,000 TJ / sec on a midsize vessel
Star Destroyer reactor energies are unknown. However, assuming that they are also based on simple fusion, then the reactor energies are going to be small, even given the massively huge reactors you could fit into a Star Destroyer . . . there would be the issue of fuel storage.
The non-canon and Warsie speculation give us a 140m main reactor on an ISD, with a peak power generation in excess of 1E25 watts, or about ten trillion terajoules per second. However, this is nonsense, since to achieve that power level with a fusion reactor would require fusing almost 200,000,000 metric tons of deuterium in one second. If they stored it in the form of lithium deuteride at 12 times its normal density (much more and you'll risk fusion via compression), that fuel would fill a container of 1000m x 142m x 142m, or almost half of the internal volume of a 1600 meter long Star Destroyer. That's for one second, and it would have to fuse all at once!
For argument's sake, let's have the ship fuse one metric ton of deuterium each second. That will give them 50,000 TJ/sec, but could only allow the ship a rough maximum of six years' duration before fuel exhaustion (assuming the "flying fuel tank" parameters mentioned above). If we instead assume that the ship isn't a flying fuel tank, but instead carries perhaps one one-thousandth that amount of fuel (200,000 metric tons (a 27.5m³ container of lithium deuteride at 12 times normal density)), the metric-ton-per-second idea now only gives them 55 hours of reactor power. If we borrow the 140 meter figure as a spherical tank (in lithium deuteride format), the ship will have a month of fuel at one metric ton per second. This would be extended to ten months if the ship only 'burned' a tenth of a metric ton per second. This gives them a fat tank, and power levels equal to the Intrepid Class starships of the Federation, at 5,000 TJ/sec . . . though without the duration. In reality, though, such a system would require multiple smaller reactors.  Again, though, this is only one estimate . . . as stated, Star Destroyer reactor energies are unknown.

Final Tally:  On an ISD, less than or equal to Federation midsize reactors, with far less endurance at similar power levels.

Shields

Advantage:
??

probably UFP
given the
firepower and type
Graviton-based, as per Geordi's screen in Generations, and capable of protecting the vessel from electromagnetic, kinetic, and subspace energies. They possess frequency windows allowing sensors to peek through, but there is apparently no easy way to determine another ship's shield frequency.  Starship shields can be brought down remotely by another starship, provided you have the prefix code and that it hasn't been changed.

(Rough dissipation limits will be added soon.)

Composition is unknown. There seems to be a peculiar shielding technique used, however, since portions of the Death Star were ray-shielded, but not shielded against projectiles. Given the bridge-tower destruction in TESB (the novel suggest the entire ship was destroyed), Anakin's flight into the cargo bay in TPM, the Millennium Falcon attaching itself to the bridge tower, and the apparent necessity of shooting the various little rocks floating about in the TESB asteroid field, one could make a defensible argument that the "particle shield" complement to ray shields is not employed very often.   Weak magnetic deflectors were observed and flown through when fighters approached the Death Star in ANH, and referred to in the novelization as the "outer shield". On the other hand, fighters were said in the novel to have collided against DS2's shield, and Anakin's Naboo fighter seemed to score knock-downs of droids with its shield, so particle shield utilization is a hazy thing.

Some have attempted to argue that SW shielding does not have frequency windows as Trek shields do . . . i.e. that SW shields are full-spectrum.  However, this is absurd . . . we can see ships when they're shielded.  That means the shields are transparent to visible light at the very least (and probably other parts of the spectrum as well for sensor usage, communications, et cetera).   This assumes, of course, that the ray shields are not limited to a certain spectrum that turbolaser weapons also must operate inside.

(Rough dissipation limits will be added soon.)

Armor

Advantage:
TIED

UFP hulls offer
more bang for
the buck,
but Empire
hull thickness
may make up for it
Federation ships use comparatively thin but tough tritanium and duranium armor, augmented by structural integrity fields. With sufficient energy input, the SIF can act as a shield ("The Chase"[TNG7]). This allows the ship to survive collision events (ST:Nem), though collisions in sensitive spots, like the neighborhood of the warp core and antimatter pods, can lead to catastrophic destruction ("The Jem'Hadar"[DS9]).

According to "Descent, Pt. II"[TNG7], the outer hull of a Galaxy class starship can withstand 12,000 degrees Celsius (and 10,000 rads of absorbed solar radiation) without even starting to glow.  "The Arsenal of Freedom"[TNG1] shows the Enterprise easily withstanding 3,300 degree hull temperatures. "Symbiosis"[TNG1] features a "very old" and virtually un-maintained sublight cargo ship enjoying 3,000 degrees while falling into a planet's atmosphere.   The ship lasts for more than a minute until structural integrity fails.

There is no canon data on armor composition. Whatever it is, it apparently isn't very helpful, since a hit by an asteroid in TESB sheared off a Star Destroyer's bridge tower and destroyed the ship. 
A temple in the ANH novelisation was described thusly: "Theoretically, no weapon could penetrate the exceptionally dense stone of the ancient temple"(178). Assuming a natural stone of normal elements, it would have to be something along the lines of the mineral iridosmine, an Iridium-osmium alloy of supreme hardness and extreme density, in the range of 20,000 kg/m³, or almost three times iron. Given that SW weapons obviously destroy SW craft with remarkable ease, one would assume a far less dense substance.
Hopefully, they armor most things better than they do their AT-STs.
The non-canon makes use of the term "neutronium", suggesting that it is the same ultra-dense compressed neutron material found within neutron stars. However, this is completely untrue.
Cloaking
Tech


Advantage:
Empire

craptastic tech, but no treaty to restrain their use
Fleet use disallowed by treaty with the Romulans.  However, the USS Defiant had a Romulan cloak on loan due to the Dominion threat, and we have seen the Federation employ cloaking technology without terrible ramifications when they mined the Bajoran Wormhole ("A Call To Arms"[DS9-6]).  A splinter group once illegally developed a phase cloak that could allow a ship to be invisible and pass through normal matter . . . one could hide within a planet ("The Next Phase"[TNG5] and "The Pegasus"[TNG7]).
Alpha Quadrant cloaking technology is available for ships of all sizes, and the cloaking devices can even cloak themselves alone ("The Emperor's New Cloak"[DS9-7]).
More here
Cloaking technology is known to exist, though its effectiveness is not known as we have never seen it employed.  We do know that the Millennium Falcon, a ~31.5 meter saucer, is considered too small to have a cloaking device.
Given the profound limitations of Imperial sensors, cloaking technology is almost certainly not so well-developed as it is in the Alpha Quadrant.
Beam
Weapons

Advantage:
UFP

better aim,
better firepower,
better finesse
Phasers are quite powerful beam weapons, with verbally implied energy levels *at least* in the high-gigawatt/low-terawatt range ("A Matter of Time"[TNG5], Data tells Geordi they must avoid a variance above .06 terawatts), though that shot apparently involved maximum power from the entire ship.
Against the sentry pods in "Conundrum", the Enterprise phaser arrays were used in a peculiar fashion. Normally, we can see the array energize at both endpoints and a beam erupt where the energy meets, but in this case the array energized and a large number of smaller beams were used. This suggests that phaser arrays may be commonly used in such a manner in the event of numerous small weak targets.
Circa 2151, starship weaponry was rated for 500 gigajoules per cannon (one terajoule per dual-cannon shot), though this could be increased to 5 terajoules per cannon at extreme risk (damage to power relays and the weapons themselves). It is logical to assume that significant advancements were made in the following 200 years.

Final Tally: Terawatt-range, minimum
(And given 100-megaton torpedoes, and the general gist from battle scenes that photon torpedos are 2-5 times more powerful than phasers, 1-10 megaton phasers (~ 4,000 - 40,000 TJ) wouldn't be too difficult to argue for at all.  That could be driven up as high as 20-50 megatons (~83 - 209 PJ (1000xTJ)) to keep with the "gist" ratio.)
Turbolasers of varying sizes seem to be the primary beam weapon, though ion cannons exist and may be deployed on some vessels. Some claim thousands of terajoules for these weapons, and the non-canon ICS claims almost a *billion* terajoules, but none of these figures have canon support. So far, the only time we've gotten a good show of turbolaser firepower against targets we can make a guess about is TESB, during the asteroid scene, and something similar is seen at Geonosis, where low-gigajoule energies are the rough minimum from a ~20m ship.
There are several sizes of beam weapon emplacement on Imperial vessels, ranging from the heavy guns on the port and starboard dorsal, to various other weapons all over the ship.   However, in the one instance the heavy guns have been seen to fire they missed a relatively stationary target, so we can only guess at their firepower, assuming they could bring it to bear.
All that having been said, the fact that weak-firepower fighters are considered a threat, even at the numbers observed, places logical limits on starship firepower.

Final Tally: Gigawatt-range, minimum.
(The highest pro-Wars estimate is below 3,000 TJ for one of the ship's largest  weapons emplacements.)

Missile
Weapons

Advantage:
UFP

better targeting,
better firepower,
better utility
Photon and the new Quantum Torpedoes are in use aboard Federation starships, with photon torpedoes being the most common by far. Photon torpedoes are projectiles capable of being fired at FTL or STL speeds at any target. Both torpedo types appear to be independently shielded, and can be used at warp to fire on sublight targets. The yield is variable, from something in cannonball range (Star Trek V), to something in the 100-150 megaton range ("Rise"[VOY3]), to many hundreds of megatons (detonation fireball very visible from planet's surface in "Skin of Evil"[TNG1]).
The "photonic torpedoes" deployed on Earth Starfleet ships in the early 2150's had yield variability such that they "can knock the comm array off a shuttle pod without scratching the hull, or they can put a three kilometer crater into an asteroid"  (Reed, "The Expanse"[ENT2]).  Common estimates place the upper-end part of the statement at about 20 megatons.

Final Tally: ~ 100 megatons (418,000 TJ), average
Concussion Missiles and Proton Torpedoes have been seen, but are rarely used. These weapons seem to be more of a surgical strike weapon, whereas Imperial beam weapons are their version of blunt-force. Capital ship missile weapons have not been observed.   Fighters have been seen to use missile weapons in ANH and TPM, but in both cases direct hits against the hull of starships were ineffective. (Proton torpedoes are also referred to as laser torpedoes in the ANH script, which may suggest something about their function.)
The highest firepower observed would be from Slave I's missile that was spoofed by spare parts.  A large fireball was created, but none of the nearby asteroids seemed to be affected.  This weapon is referred to in the script as a "guided aerial torpedo".

Final Tally: ? . . . kilotons?
Weapons
Ranges

Advantage:
UFP

ducks in a barrel
Many (but not all) impulse battles occur at severely short ranges.   We have seen weapons used at impulse to have profound ranges ("The Wounded"[TNG4], "Return to Grace"[DS9-4], "The Search"[DS9-3], etc.), in the area of 100,000-250,000 kilometers. However, weapons limited to lightspeed would take a third of a second to cross a 100,000km distance, so maneuverable Trek targets engaging in evasive maneuvers could evade (especially given that phasers do not move at lightspeed, canonically). "Elaan of Troyius"[TOS3] shows the Klingons firing at about 80,000 kilometers.
At warp, torpedo ranges are at least 5 million kilometers ("Human Error"[VOY7], with similar range shown in "Flashback"[VOY3]). Phaser maximum range at warp is unknown.

Maximum Range: ~200,000 km (STL only), Effective Maximum Range: 10-200,000km (variable).
All battles in Star Wars occur at slower-than-light velocities, and weapons ranges are perilously short. On smaller craft such as the Millennium Falcon, maximum weapons range for a target which is almost stationary relative to the Falcon is on the order of a couple of kilometers (200 meters, actually, but I'm being generous), which seems true for fighters as well. 
Capital ships would presumably allow for bombardment of a planet from orbit (100-1000km), but actual ship-to-ship combat ranges have not been seen to exceed 100 kilometers. (The longest observed starship weapons range was a TF battleship firing at about 60km in TPM.) The point-blank affair seen in ROTJ (around two kilometers) is unusually close, however.
The Death Star destroyed Alderaan from within six planetary diameters, which (assuming Earth's diameter) would be just under 77,000 kilometers, the maximum seen from any SW weapon.

Maximum Range: ~1,000km (?), Effective Maximum Range: ~100 km
FTL
Drive

Advantage:
??

UFP can go
faster, but the
standard
speed seems
higher for
Empire

also, warp allows for interaction with realspace (attack), but hyperdrive renders one impervious
Warp drive, using some sort of "continuum distortion" via subspace fields, allows the vessel to achieve speeds of several thousand times that of light in realspace. Verbal references suggest that the ships of the Federation are capable of traveling up to about 1 light-year per hour (Galaxy maximum of 9000c as per "Where No One Has Gone Before"[TNG1], slightly better than the speed of the Kelvan-enhanced Enterprise in TOS). Newer ships such as the Intrepid have higher maximum speeds. For example, In "The 37's"[VOY2], Paris says warp 9.9 is 4,000,000,000 miles per second, or 21,400c (2.45 ly/hr). In "Encounter at Farpoint"[TNG1], Data reported that they could make warp 9.8 "at extreme risk", but the maximum warp red line appears to be 9.2.  "Maneuvers"[VOY2] has Voyager traveling 2 billion kilometers/second, or about 6700c, though no warp speed is given at the time.  In 2152, the Enterprise NX-01 demonstrated the ability to achieve a speed of 1460c (12 light-years in three days) in "Cease Fire"[ENT2], and this was presumably her maximum (warp five) thanks to the overworking of the injectors.
Note that the Intrepid Class is capable of a sustainable cruise velocity of warp 9.975 ("Caretaker"[VOY1]). On the other hand, "Unimatrix Zero" uses the 9000c figure from "WNOHGB" again as a maximum speed, saying that it took the ship two hours to travel two light-years.  As for lower warp speeds, we have "The Most Toys"[TNG3], where the Jovis's warp three speed calculates out to a mere 39c.
None of these are dead-firm figures, however. The Enterprise-Prime would take 11 hours to travel 990.7 light-years in "That Which Survives"[TOS3], suggesting 90 ly/hr, or 788,400 times lightspeed. "Bread and Circuses"[TOS2] has the Enterprise cross .2 light-years in about a minute, suggesting a speed of 107,000c. Even the runabouts, apparently capable of warp five or so, were seen to make 30,000c if not more ("Whispers"[DS9-2]: 1.23 hours to a planet no less than a little under five light-years distant).  Then, of course, there's the Star Trek V incident, where a trip to the center of the Milky Way from Nimbus III (which could be no less than 17,000 light-years from the center, as per First Contact) took under seven hours. That suggests a speed of over 2500 ly/hr, over 20,000,000c! (Which, entertainingly, is just about what it would take for stars to float past a la TOS.)
Then there's the opposite side of the coin. "Fight or Flight"[ENT1] gives us a value for warp 4.4 of 30,000,000 km/sec, or almost exactly 100c, though the rest of the series contradicts this value.  In "Bloodlines"[TNG7] Riker calculated in his head the time required for the Enterprise to travel 300 billion kilometers at Warp 9, and gets about 20 minutes, which would be about 900c, or .1ly/hr. In "Caretaker"[VOY1], Janeway said that at "maximum speeds", it would take 70 years to make the 75,000 light year journey, which works out to only .12 light years per hour, or just over 900c.  That contradicts other maximum Voyager values . . . perhaps she was including stops, or calculating with a warp six velocity.
The common theory used by fans to reconcile all the variable speed figures is the idea of "warp highways", areas of space where warp drive works especially well. These are often thought of as roughly linear phenomena, but could also simply be large patches of space. However, there is nothing in the canon which makes any reference to this concept. Taking all the data, it would seem that older Federation ships are limited to the 10,000c range (about 1.1 ly/hr), with newer ships limited to the 21,400c range (about 2.45 ly/hr). Cruising speeds are probably closer to 2,000c. But, I'll have to go with the Tech Manual on this one and say that your mileage may vary.

Final Tally: 
~ 21,000c (fast ship at warp 9.9) 
~ 9,000c (slower ship max at warp 9.2)
~2,000c (common velocity?)
Hyperdrive apparently (hopefully!) uses some sort of extra-dimensional space-folding technology, since Han comments that his ship is only capable of ".5 past lightspeed".  Notice that he also refers to making the Kessel Run in 12 parsecs, which is a distance, not a time or speed. (It should be noted, however, that the script has the following to say about that line: "Ben reacts to Solo's stupid attempt to impress them with obvious misinformation.")  Hyperdrive would, however, offer virtual invulnerability to attack, so long as you stayed in hyperspace.  Hyperspace may also involve a time dilation effect for those travelling within it.
In any case, the size of the Empire suggests effective hyperdrive speeds at least on the order of warp drive.
Actual hyperdrive speed estimates from the canon are difficult. The entire Star Wars canon saga has so far only covered a dozen planets, and we don't have much information on distances.  We do know that Tatooine to Geonosis is "less than a parsec" in AoTC, and TPM establishes that Tatooine is closer to Naboo than Coruscant, and can be reached with a "leaking" hyperdrive. The impression given in AoTC is that the "less than a parsec" trip between Tatooine and Geonosis took about 15 hours (more on this here), implying a speed of around 1752c.  The Rebel fleet hyperspace trip in Return of the Jedi demonstrated a speed on the order of 11,000c, however.  If the Millennium Falcon were taken to be .5 times faster than the rest of the fleet in RoTJ, it would be capable of 16,500c.
(Note: Some argue that the use of the phrase "halfway across the galaxy" in AoTC implies huge speeds. However, the evidence points to lesser speeds. This is not anti-Star Wars thinking . . . I attribute Captain Pike's comment about Earth being "at the other end" of the galaxy from Talos to be similarly full of hyperbole.)
The non-canon gives us wildly variable figures, from about 2.4 light-years per hour (21,000c) ("Heir to the Empire") to 127 light-years per hour (just over 1,100,000c) ("Dark Force Rising"). The "Behind the Magic" CD-ROM suggests speeds variable based on local conditions, from 600,000 to 50,000,000c (Milky Way to Andromeda in 19 days). However, there is nothing in the canon to support these figures. (Entertainingly, though, some claim that there is canon evidence for such speeds, and they base this off of non-canon maps and charts using incorrect galaxy data. Further, the BTMCD information was contradicted in Attack of the Clones.)


Final Tally:
~ 16,500c (fast ships (est.))
~ 11,000c (standard?)
~ 1752c (slow ships).

STL
Drive

Advantage:
UFP

runs circles
around the
Empire
Impulse engines are used, and ships seem to use an artificial mass reduction effect to conserve fuel and enhance acceleration. This renders impulse "not-quite-Newtonian". This also explains the apparent use of "one-quarter impulse", "half-impulse", and such as speed estimates, and not acceleration. You could, for example, fire a brief thrust, then turn on AMRE and suddenly start zipping along when your mass lightens. Federation ships have incredible advantages over Imperial ships in acceleration, as observed in TMP (half lightspeed in no time flat, bare minimum 34,000 m/s² acceleration), "Peak Performance"[TNG2] (the E-D zipping around a planet in no time flat), "The Swarm"[VOY] (some calcs suggest 4000km/s²), and so on. 
Further, Federation starships could run circles around their Imperial counterparts.  At Wolf 359 (as depicted in "Emissary"[DS9]) we see two of the largest ship classes, Ambassador and Nebula, flying in tandem.  They both execute remarkably quick and tight 120-degree turns.  (A 3ivx version is here, and an animated .gif here.)

Final Tally:  Starships are capable of accelerations of thousands of m/s, and offer profound maneuverability.

Similar to Impulse, but involving big honkin' thrusters on the back on every observed ship type except for TIE fighters, which have two smaller ion engine apertures. The Falcon's engines are also ion engines.  These huge engines, and comparatively small observed speeds, suggest a less-advanced, possibly straight-Newtonian, approach.  Some SW ships, however, are quite maneuverable given their bulk (Home One turn in ROTJ). However, that might have involved use of repulsorlift tech (see below), given how close they were to the planet. In open space, Star Destroyers are referred to as sluggish and slow to respond in the TESB novel, incapable of avoiding a very damaging collision in TESB.  
Some claim that a screen in ROTJ showed the Imperial Fleet making a maneuver that would have involved acceleration of 30 km/s^2. However, the script has Leia reacting as if its the Rebel fleet approaching through hyperspace.  In neither the film nor script is Leia shocked as if she's seeing an Imperial fleet's trap (in the novel, the Rebels have arrived and combat is in progress).

Final Tally:   Starships are sluggish and generally not that maneuverable.  Even small, fast ships like the Falcon can only make accelerations of a few hundred m/s.

Antigravity
Technology

Advantage:
Empire

more and
bigger
Use observed on shuttles and in a variety of smaller applications throughout Trek since the 2260's. Flying vehicles akin to those in AoTC were observed in the 2151 scenes from "Shockwave"[ENT1], and of course the shuttepods also seem to use antigravity, but the precise nature of their technology is uncertain.

Intrepid Class starships, at 700,000 metric tons, have been seen to land on four little-bitty feet. All told, that's basically akin to having nine or ten Enterprise Class aircraft carriers, or 15 Iowa Class Battleships, or 2,102 Boeing 747's strapped together and sitting on an area about the size of a house or two.   Thus, despite the constant mention of thrusters when landing, it is clear that some sort of antigrav or mass-reduction system must be in constant operation when the ship is landed.  (The same goes for the lack of a plume or blast wave whenever the ship takes off.)
(Update:  "The 37's"[VOY2] makes reference to "antigrav thrusters" during landing . . . a curious phrase, but it fixes things.  These would, evidently, be the sort of thrusters they're always talking about when Voyager is landing/taking off.)

Further, compare Voyager's landing ability to the Galaxy saucer crash plan. If the Federation had cheap and easy antigrav tech at the time, one would think they'd have employed it on the latter.  Indeed, if we were to completely guesstimate the saucer density as being akin to the Intrepid's, she should weigh in at about 4,283,064 metric tons.    Perhaps the Intrepid is within a mass limit, or else all the extra mass/volume of the antigrav units they'd require for the saucer were considered too big a pain.   I really wouldn't expect Starfleet to say "sorry, you've gotta crash your kids" unless they had to, though.

Final Tally:   Anti-gravs have been seen to be employed on vehicles of up to 344 meters in length, at a mass of 700,000 metric tons.

Antigravity "repulsorlift" technologies are used within six planetary diameters, even by larger ships (ANH novel, 115-117). Many larger vessels can and do land, a necessary evil without transporters. However, ships such as the "galactic cruiser" (aka Corellian Corvette) seen in the beginning of ANH cannot enter atmosphere without a "stabilizer fin" (ANH novel, ch. 1). How antigravs work is unknown, but it does have to have a decent gravity field to push against, according to canon sources.
The largest vessels seen to land thus far are the 700 meter Acclamators, ships twice as long as the Federation's Intrepids.

 

Final Tally:   Anti-gravs have been seen to be employed on vehicles of up to 700 meters in length, and are far more commonly used in such large applications.

Sensors

Advantage:
UFP

better range,
more capable


Barring interference (natural or artificial), even Starfleet ships of the 2150's could read the DNA of the crew of opposing ships ("Silent Enemy"[ENT1]), and could scan for weapons and hull composition of a ship warping toward them, even when it was two hours distant (at lightspeed, that's 2.1 trillion km) ("The Xindi"[ENT3]). By the 2360's, scanning a foreign probe or ship could allow a determination of where it has been ("Bloodlines"[TNG], "Chain of Command"[TNG]), and sensors of the 2370's (if not before) had enough resolution to transport someone when the beaming ship was passing by at at least lightspeed ("Maneuvers"[VOY2]). "Routine" scans have a radius of three light-years ("Skin of Evil"[TNG1]).  Sensors can record the position and trajectory of individual particles of interstellar hydrogen, engine exhaust, and space dust ("The Battle"[TNG1], "Relics'[TNG5], ST:FC), and note disturbances in that. The primary weakness of Federation sensors seems to be that crew isn't always looking for a particular something, and therefore does not see it ("The Hunted"[TNG3]). Given the massive amounts of information sensors provide, this does point to a weakness, though sensor logs seem to make this information available for later analysis assuming it isn't too late. Sensitive border regions have numerous sensor buoys ("Preemptive Strike"[TNG7]).
As of "The Wounded"[TNG4], sensor range on a GCS was 10 light years, when looking for a fellow Federation starship that did not wish to be found.  Longer ranges have been observed in other circumstances.  One of the more notable is "The Raven"[VOY4], wherein they scanned for Borg vessels within a range of 40 light-years.

Final Tally:  The sensors are extraordinary, though there are times when the information processing could be better.

Cannot track ships accurately at FTL speeds (ANH Novel). Dedicated communications ships can jam most SW sensors (ROTJ novel, 191-193), and the Death Star used some sort of distortion field that confused the instrumentation of nearby Rebel *and* Imperial ships, causing people to have to look around to see who was shooting them (ANH novel, 174). (This may have been the magnetic field the fighters flew into.) Imperial vessels have difficulty tracking movements up or down (i.e. perpendicular to their flight path) (ROTJ novel 191-193). Cloaking devices are mentioned in the movies, though whether it is an invisibility screen or simply a sensor jammer is uncertain. There is no evidence for FTL realspace sensor systems, meaning that if a Star Destroyer is sitting in space, it apparently would not be able to see anything coming in at lightspeed or warp speed until it was already there, just as occurs with hyperdrive.
Maximum sensor range is unknown, though one would not expect it to be profound given the rest of the facts.

Final Tally:  The sensors are very poor, with some odd limitations.  ISDs don't even have hull contact sensors, unlike Earth's NX Class of the 2150's.

Fighters

Advantage:
??

quality
vs.
quantity

The Dominion War saw extensive use of small (~30 meter) "tac-fighters", armed with shields, phasers, and small torpedoes. Though these are commonly referred to as fighters, they seem to be more along the lines of somewhat smaller-role PT boats (i.e. the WW2 small, fast, ~24m wooden boats with four heavy torpedoes aboard, any one of which could take down or severely damage a battleship). Such ships had existed for some time prior, given their use by Maquis forces alongside the large Maquis raiders.  Their use by Starfleet is controversial, given the low survivability against Cardassian capital ships. However, they were able to dish out moderate punishment, even on Galor Class Cardassian vessels. Firepower estimates are going to be questionable, since we've never seen them fire against a target we know much about.
Runabouts are not commonly used in the fighter role, though this is not unheard of ("The Jem'Hadar"[DS9-2]). Runabouts are remarkably tough little ships. They have strong shields (successfully withstanding several hits from a Jem'Hadar attack fighter in "Treachery..."[DS9-7]), and very good phaser coverage.  At least some have torpedoes ("Past Prologue"[DS9-1]).
Shuttles have never been observed in the fighter role, though most seem to be armed and lightly shielded. Firepower figures for shuttles are not known, but "Detained"[ENT1] shows us a shuttlepod with weapons at least in the ~50 megajoule range against what are presumed to be simple concrete walls, so anything less is quite unlikely.
Peregrines, runabouts, and some shuttlecraft have warp drive.  Runabouts are capable of no less than warp five ("Dax"[DS9-1]), while Type-9 shuttles are capable of warp four ("Resolutions"[VOY2]), and have a range of no less than 6.7 light-years ("Renaissance Man"[VOY7]).   The sublight accelerative capabilities of these vehicles are not definitely known, but would be expected to be at least on par with the larger starships.
The Empire uses a variety of small (~6m) TIE fighters and TIE bombers. Most TIE vessels are unshielded, and the most common TIE fighters have two small weapons on the central sphere with limited off-axis firing ability.   A direct hit from this weapon can severely damage an R2 unit, or cause an explosion of an X-Wing's engines (ANH), implying that the weapons are not that powerful.  Naboo and Trade Federation fighter weapon output from a few decades earlier were decidedly sub-kiloton, probably at a parity with 2150's shuttlepods; there is no indication of significant advancement in that area in the intervening SW decades.
TIEs are capable of atmospheric flight, as seen in TESB, and would thus seem to have repulsorlifts, but are not commonly equipped with hyperdrive capability.  The prologue to the RoTJ novel explicitly defines TIE as "Twin Ion Engines" . . . NASA probe Deep Space 1 uses such a device, though we can of course presume that TIEs feature much-improved versions.
TIE fighters seem to have lesser acceleration capabilities than the Millennium Falcon, which suggests top-end acceleration of a couple of hundred meters per second.
Tactics

Advantage:
UFP

UFP has range,
maneuvering,
fleet experience,
no fear about
point-blank,
and would laugh at the fighters
The Federation has a large amount of experience with massive fleet engagements (DS9), bringing into play an amalgam of tactical and strategic concepts from air, sea, and land. Weaknesses are calculated (Riker and the Tholian blind spot, Riker in "Best of Both Worlds"), and exploited (ST2, "BoBW", Phoenix vs. Cardassian weapons range in "The Wounded", Hathaway vs. Enterprise-D in "Peak Performance", Defiant taking position on a Bird-of-Prey's underdefended rear in "Way of the Warrior", Sisko in "Shattered Mirror").
Warp strafing of sublight targets has also been observed ("Elaan of Troyius"[TOS], "The Ultimate Computer"[TOS]), monopolizing on an impressive speed advantage in realspace. 
With the transporter, ships can be boarded when their shields are down or unable to prevent beaming, allowing opportunities for capture or mayhem ("WotW", "Return to Grace", "BoBW"). Transporters are also useful for weapons delivery ("Dark Frontier"[VOY]).
As a last resort, ramming is not unheard of ("BoBW", "Caretaker"[VOY], ST:FC, ST:Nem).

Fleet encounters usually end up as close-range affairs, either to preclude the use of torpedoes (known to be unsafe if fired at extremely close range), or to preclude the use of fleet fire concentration on individual ships.

 

Fleet engagements are a virtual unknown in the Empire, which has not been seen to mass a fleet of more than 27 ships in a single engagement (ROTJ). The Emperor's Fleet (TESB novel) consists of merely the six ships at Hoth, with fighters, and is considered a "great space armada"(209).
The Empire fields two main classes of capital ship, the common Imperator Class Star Destroyer (in two observed variants), and the far larger "super Star Destroyer", Executor Class. (Note that "Imperator" and "Executor" are non-canon class names.)  
Fleet formations seem to involve a roughly spherical distribution of lesser ships around the command ship. Given the Imperial dependence on fighters and fighter harassment of capital ships, this makes a great deal of sense, since it would help shield the command ship against fighter attack.
Maneuvering tactics are almost non-existent, in part due to the bulk, sluggishness, and relative slowness of the ships. Ramming is referred to in the RoTJ novel as the last-ditch maneuver of a burning starship, and reference is made to the use of abandoned cargo ships loaded with charge, set on collision courses.  However, given the fragility of Imperial ships (as per the Executor crash, etc.), ramming could only be a suicide tactic.

Bringing capital ships to within a couple of kilometers range of one another was virtually unheard of prior to Return of the Jedi.

Ground
Combat

Advantage:
??

quality
vs.
quantity
From what we've seen, ground combat is not favored as much as air/space superiority.  We have not observed Federation tanks or armored personnel carriers (besides when shuttles are used in that role, as per ST5), though "hopper" troop transport and landing craft were mentioned in Deep Space Nine, and opposing forces are said to have such things.  Ground combat involves the use of hand phasers, phaser rifles, and powerful photon grenades, with launchers ("Arena"[TOS1]), though a surprisingly wide variety of hand weapons are in the arsenal of Federation ships (First Contact, Insurrection). Stun grenades and remotely detonated charges were used in the 2150's, and the latter have also been seen on Voyager.  Personal forcefields have been mentioned ("Homefront"[DS9-4]), but not observed in use.
Nemesis is supposed to show us the first observed Starfleet land vehicle, a glorified dune buggy with a phaser mounted on it. Shuttles are more commonly used for ground support, as seen in "Detained"[ENT].
More here.
The Empire has a great deal of dedicated ground war equipment, from the huge 20 meter tall All-Terrain Armored Transport (AT-AT) walkers to smaller AT-ST (and perhaps older AT-TE) walkers, with landing craft that can deploy them. Use of air support seems lacking in the time of the Empire despite the existence of TIE bombers, though the Republic did use vehicles similar to Hind attack helicopters in Attack of the Clones. AT-ATs are large, slow targets, only capable of 60 km/hr according to some sources (a few km/hr slower than a modern tank), and how they disembark whatever they are transporting is a mystery . . . we've only seen a side door. Ground equipment seems to be armored, but is not shielded.
Mines and
Other
Ordnance

Advantage:
UFP

cloaked
self-replicating
mines beat
 wimpy and
 2-D bombs
The Federation rarely employs mines.  However, they did mine the Bajoran Wormhole ("A Call to Arms"[DS9-6]).  Discussed at the time were "pulse mines", but instead the DS9 team decided on and constructed numerous mines of dizzying capability.   No more than a meter across, they were mobile, set to swarm against enemy ships in groups of 20-30, and if the enemy tried to poke holes in the minefield, the mines could make use of on-board replicators to re-create fallen comrades.  Last but not least, they each carried a cloaking device so that, when activated, the field was invisible.
Cloaked minefields were nothing new, of course.  The Romulans were employing them as early as the 2150's, and the Klingons were working on wrapping the entire Bajor system with extremely powerful cloaked mines, deployed from cloaked ships, during hostilities with the Federation ("Sons of Mogh"[DS9-4]).  Even at a destruct range of ten kilometers, an accidental detonation tore open a Vor'Cha Class Klingon attack cruiser, leaving a gaping hole in the ship.
Bombs, in the classical sense, have never been seen in use by Federation vehicles.
Special double-hulled TIEs have been observed dropping/launching some sort of bomb on asteroids (when trying to flush out the Millennium Falcon in TESB).  These weapons made a fighter-sized blue flash, but were curiously ineffective at doing any observable damage to the asteroid.
Larger bombs may be in the Imperial arsenal . . . in the TESB novelization, the TIE bomber scene occurs at another time, the bombers being replaced by Star Destroyers dropping bombs.  The description of the bomb's effect on the asteroid's surface and the Falcon below is much more violent, though still relatively tame.
In AoTC, we get to see seismic charges.  These are ~1m peculiar tumbling devices which emit a bright flash, followed by a two-dimensional destructive shockwave.  The script calls them "sonic charges", as does the novelization half of the time. The operational theory behind these devices is not clear -- sound does not commonly propagate in two dimensions, or in the vacuum of space.  In any case, the weapons had an impressive effect against the rocks along the two-dimensional shockwave, producing a great deal of fracturing with traces of molten material at the shockwave-touched fracture lines.  Careful scrutiny also shows some dust kicked up off of nearby rocks before the shockwave appears . . . this dust seems to get sucked toward the epicenter before being blown away from it.  
The effect of the seismic charges against a vessel (especially shielded) are not known, but the dust-off effect did not seem to affect Obi-Wan's fighter.  In open space, simply avoiding the plane of the shockwave would seem to ensure safety.
Weapons of this type or comparable yield have never been seen in use by Republic or Imperial forces. 
Special
(but common)
Tech
The transporter definitely comes to mind. After 200 years of use and development, beaming is quite commonplace.  Geordi, in "Realm of Fear"[TNG6], says millions transport daily. Maximum transporter range is about 40,000 kilometers, as per "A Matter of Honor". Transporters have spawned spin-off technologies such as the replicator. Industrial replicators can do wonderful, wonderful things for an infrastructure. The Federation gave Bajor two industrial replicators for their rapid rebuilding project.   After the aborted Klingon invasion of Cardassia, which left the industrial base of dozens of Cardassian worlds destroyed, the Federation was to have given them twelve such replicators of the same type for the building of power plants and factories.  
Indeed, the number of man-hours a replicator would save cannot be overemphasized.
One could say that another spin-off of the replicator was seen in Rom's self-replicating mine design.
Death Stars I and II, with the second one capable of firing smaller bursts at individual ships. I rate these as "common", even though they can't be built too quickly, requiring "many long years of secretive construction"(ANH novel, 31), or at least three years of less secretive construction for one described in the RoTJ prologue as "nearly twice as big as its predecessor [...] but more than twice as powerful".  (Whether that refers to its utility thanks to fleet combat capability or directly to its reactor energy is unknown.)
The firepower of the Death Star 'superlaser' is not known quantitatively, but qualitative estimates of Alderaan's destruction were made by Han in the ANH novel: "No...the entire Imperial fleet couldn't have done this. It would take a thousand ships massing a lot more firepower than has ever existed"(102).
People commonly use as a basis of calculation the gravitational binding energy of an Earth-like world (1E32J) and the energy that would be required to get planetary debris moving as observed (for a grand total of 1E38J). However, the "ring effect" of the planet and Death Star explosions indicate that the Death Star superlaser is not simply a direct-energy-input weapon, but achieves its goal through some peculiar energy technique or physics effect that is not known. This is confirmed by a wide variety of observations. More on this here.
Other
Special
Advantages
Medical technology and knowledge seem to be far more advanced in the Federation. Compare the ability to repair almost any non-lethal wound to the use of artificial mechanical limbs, peculiar medical watertanks filled with bacta, and Darth Vader's suit in Star Wars. Granted, they are advanced artificial limbs, but artificial limbs all the same.   

Holodecks, exceptionally useful for training, could also be very useful for interrogation purposes.

Starfleet ships are capable of precision attacks to disable enemy ship systems ("Shockwave"[ENT], "The Defector"[TNG], "The Wounded"[TNG], etc.), whereas the Empire seems capable of just firing and hoping for the best (ANH).

Starship Flexibility: With rare exceptions, we seldom see a single-role starship. We've seen dedicated transports and science vessels, but even Federation warships such as the Defiant are capable of performing scientific duties.
The Force and lightsabres. It is difficult to ascertain the effect the Force might have, but there *are* only two Sith at a time, and their powers obviously didn't allow them to prevent the formation and continuation of the Rebellion before Luke's arrival.  However, the Emperor is said in the RoTJ novelization to be the force holding the Imperials together . . . his death causes chaos among the ranks.
Similarly, there are presumably only two lightsabres in the Imperial arsenal, but if these were made more common, they would be profoundly effective in melee situations. Mere bat'leths would pale in comparison.
Droids, though subject to electronic hallucinations (ANH novelisation, p. 9),  may also present quite an advantage (especially in regards to manpower), though apparently few are as sentient, intelligent, and resourceful as C-3P0 and R2-D2. On the other hand, most people in the Republic thought droids couldn't think at all (Dex and Obi-Wan, AoTC).
In hand-to-hand combat, one would assume that the Stormtrooper armor would provide some assistance, even though it is apparently not sturdy enough to ward off simple spears (ROTJ), and has been seen to crack with limited damage.
A wide variety of weapons emplacements give the vessels of the Empire very good coverage, though the heaviest and most visible Star Destroyer weapon emplacements are limited to the dorsal firing arcs.
Hyperdrives are carried internally, whereas the Federation ships require large external nacelles. This should make them harder to damage, at least on larger ships.
Cloned and "programmed" soldiers are a profound advantage, despite the lack of the training ability afforded by holodecks.
Other
Special
Disadvantages
In a situation where transporters are useless, Federation ships must rely on a comparatively small number of auxiliary craft. However, these craft are better protected than their Imperial counterparts, and larger vessels such as a Galaxy Class carry Runabouts, surprisingly tough little craft (or, technically, ships). Though shuttlepods (such as the ones from Enterprise and the little boxy ones from TNG) are not warp capable, shuttlecraft are. Voyager's Type 9 (speedboat) shuttlecraft have a range of at least 6.7 light-years, as per "Renaissance Man"[VOY].

Federation warp engines make large targets.  Really huge.  Downright massive.

Due to the lack of transporters, Imperial antigrav technology seems to have a definite edge. Therefore, large Imperial vessels could engage in maneuvers within planetary atmospheres that only ships such as Starfleet's Intrepid and Nova classes could hope to match.
The Federation has a ridiculous number of ship classes (based on all the weird kitbashes used in some of the fleet shots and in the Wolf 359 wreckage scenes), though these oddballs seem to be rare compared to Excelsiors, Mirandas, Akiras, and so on.  Nevertheless, this would almost certainly wreak havoc in regards to starbases keeping parts in stock, or repairing various ships.
One would think that the larger ships must have a horrible response time to emergency conditions. Not only does the Empire still use gunnery crews on the ship's periphery (not used in Trek since TOS in favor of direct weapons control from the bridge), presumably due to unreliability of computer targeting (ANH novel p. 285), but ships of such colossal size would make "Imperial Rapid Response" an oxymoron.
The large bridge windows of Star Destroyers are referred to in the TESB novel as a severely weak point, compared to the hull . . . this was proved by the A-Wing that destroyed the Executor's bridge (and shortly thereafter the Executor) in ROTJ.

Those huge sublight engines make huge targets. Really huge. Downright massive.

A few general observations:

1. It is often suggested that Federation transporters would have no trouble with Imperial shields. Actually, the record of Starfleet vessels beaming through unknown shielding is more of a hit-or-miss affair. As far as hits go, the Enterprise-D beamed effortlessly through Borg shields, until they adapted. They were also able to find a way to beam through the planetary shields of planet Aldea, which is rather impressive given the technology level of the Aldeans. On the other hand, Gomtuu's shields were impenetrable, which is a miss. One basic issue involved is that in most situations involving unfamiliar shielding, transporting through them is often not discussed, especially in tactical situations.

2. "Statistical Probabilities"[DS9] was referring to Federation casualties only, though this was not explicit in the conversation between Bashir and Sisko. However, when Jack and Lauren are discussing handing over Starfleet's battle strategy to the Dominion (thereby trying to make the conflict end in weeks, and thereby be less bloody), they explicitly refer to 'only' 2 billion Federation casualties, as opposed to 900 billion.

3.  Some argue that SW planetary shields are suggested in the prologue of the canon novel of RoTJ.  This is not the case:  "the view-screen depicted the battle station itself, the moon Endor, and a web of energy—the deflector shield—emanating from the green moon, encompassing the Death Star."