I've played KDF to T5 in the beta going down the Bcruiser/Carrier route and since early start hit i've played KDF to T3 as Sci/BoP and T3 as Fed as Sci/Sci.
I'm not sure how it is for people on the fed side who play in cruisers and Escorts but as Science i find PvP to be a piece of cake compared to my experiences on KDF side. I can tank as well if not better than the Battlecruiser, see cloaked enemies a mile off, absolutely destroy any player/ship class combo in 1 v 1 and very often even 1 v 2, damage is through the roof with a single EPS console due to beam angles, c'mon being first or second in damage almost all the time on a ship where i spend a lot of my time healing/buffing/debuffing/CC'ing?
T1 & 2 i wasn't doing as well in the sci vessel but T3 came along and honestly the ship is way overpowered for what it is and has many many more advantages over any ship the KDF get up until Carrier, with the recent changes to cooldowns on the carrier that might even be true there too now.
From T3 Feds have KDF at such a disadvantage it's not even funny, the fact that KDF players think/say things are balanced from then on is simply testament to them being better players in general and most Feds being out of their league.
Edit - I know gear is a dead horse subject, but the amount of blues you get on the Fed side is unreal you get blue almost everything mostly via quest and some through drops. Some of it has insane extra stats like blue heavy cannons with +15 turn rate as bonus stats lol.