Ok, so this has been out for 2-3 weeks and I have put in 100+ hours. This is one of the best Multiplayer FPS's I have played in a VERY long time. My only real beef with it is the lack of map rotations, and I'm not even sure that's a fair complaint. There are 7(?) maps, and 4 game modes for each map that dramatically change how it is played. Rush needs some serious balancing at the moment, its almost impossible to win right now.
The game is incredibly fun. No golden bullets. The battlepack system is tons of fun and let you optimize a specific gun if you choose to.