The game's server issues are getting fixed by DICE and EA. They probably weren't ready for a giant influx of players.
I still think EA should have kept with GameSpy instead of trying their own master servers, considering it was so goddamn hammered and they had to keep adding more hardware.
Anyway, I'm grinding my Assault up to the top, then my medic, recon and engie.
Shotguns only work in defence and you're actively camping your objectives.
That, and lots of well placed C4.