I've been playing Seraphim almost exclusively pretty much since FAF started and I have to say, they are a lot better than 3599 because most of the bugs have been fixed, but they seem decidedly weaker than the other factions. Seraphim isn't without strengths, but the weaknesses outweigh them by a large margin, I think.
T1 land: Slight strength. Not as good as UEF, but the combat scout makes up for a lack of LAB.
T1 Air: average. The T1 bomber is arguably the best of the bunch as is the T1 transport and the T1 air scout, but the lack of a ghetto gunship/regular gunship is substantial enough to counterbalance that.
T1 naval: Substantial weakness: The frigate can't fire straight forward, which isn't a huge problem, but the sub has 2/3rd the normal HP and is completely owned in sub-vs-sub battles.
T1 structure: Same as the rest
T2 Land: Slight weakness. The T2 bot is about the best T2 direct fire unit, but the lack of a support unit (shield, stealth) and the worst T2 amphibious tank make this an overall weakness.
T2 air: slight Weakness. The gunships is average. The T2 fighter bomber is a good bomber, but the almost useless torp bomber is too big a weakness. 420 mass for a 1200 damage bomb that can be dodged versus a 240 mass for a 750 damage torp that can't be dodged is actually a big ripoff and simply doesn't work well vs navy.
T2 Naval: Severe weakness: The cruiser's bombardment weapon can be stopped by a single TMD and the cruiser itself has abysmal hp at only 2400, compared to 3000 for more other cruisers. The AA weapon isn't worse, just different, but the other aspect of the cruiser are worse. Also, the T2 destroyer loses to every other destroyer in a 1v1 and, again, Seraphim does not have any T2 naval support units (no sub hunter, no shield boat or stealth boat).
T2 structure: Slight advantage. A strong shield, beam PD and strong TMD make the T2 structures an advantage.
T3 land: Average. The tank/sniper combo is average. The benefits of the T3 mobile shield are outweighed by its enormous energy cost to use (-300).
T3 air: Substancial Weakness. The only faction without a T3 gunship or a special ability (T3 torp bomber for aeon, T3 transport for UEF, T3 air stealth for Cybran)
T3 naval: Substancial Strength. Average battleship but really strong T3 sub hunter. Battleships nuke capability is counterbalanced by the fact that the nuke costs 19200 mass per missile as compared to only 12000 for a stationary launcher. The carrier is the most useful of the non-XP carriers, but that's not really worth much because all of them suck.
T3 structure: Average. The best T3 shield is counterbalanced by a complete lack of any intel enhancers, (eye or rhianne, soothsayer) or engineering stations.
So to count them:
1 slight strength
1 substantial strength
2 slight weaknesses
2 substantial weakness
That wouldn't even be so bad if there wasn't a weakness in 3 out of the four areas of tech 2 (Land, air and naval). Serpahim just gets killed at tech 2 at the moment, so I'd like to recommend a few adjustments to help change that.
First, to address the T2 land weakness, just making the T2 hover tank a little bit better can, imo, help out.
-Range from 18 to 23. This would basically put it more on par with the aeon T2 hover tank (range also 23) while keeping the faction diversity (different fire cycle... one damaging shot for 175 versus many quick shots.)
To address the T2 air weakness, making the torp bomber projectiles immune to anti-torp would be sufficient. It would still be worse than the Cybran/UEF versions because, like he aeon variant, it would fail in shallow water, but at least it would be as good as the aeon version rather than much worse.
To address the naval weakness, I recommend a buff to the destroyer. First, a slight damage buff to one of the two guns to even them out. One gun does 42 and the other does 47. I'd change the first one to also do 47 damage. The second change would be to increase torpedo DPS from the 66 it is right now to about 100, to put it on par with the Cybran destroyer in terms of torpedo DPS and allow seraphim to combat T2 subs.
Lastly, a small buff to the T1 sub by increasing the fire rate of the T1 sub anti-torp from 20 secs to 5 secs would help make the T1 subs less weak.
With these changes, keep in mind that Seraphim largely lacks the unit variety that other factions have, so if a unit appears stronger than its equivalent in another faction, that it can still be balanced. Seraphim doesn't have a T2 long-range bot, a T2 land support unit, a T2 sea support unit, a T3 strategic missile sub, a T3 sonar, a T1 ghetto gunship, a T3 gunship, a T3 heavy assault bot, or any special T3 air ability (T3 torp bomber, T3 transport, T3 air stealth). Also, keep in mind that Seraphim lacking units, having weak units and just all-around sucking is not "faction diversity".
So... opinions?