Exactly same thing with me, ive tried all the classes (medic is so the way forward), but really want to wait for release now so i can batter my character!
Medic is the way forward for me also, I find you can just live for so long. Team up with a decent assault and you melt faces, I think I have like 30 assists a game a few days ago just healing an assault! Also once you start getting poison aura and grenade you really start dealing some damage also.
Roll on release date!