Medic is prob my favourite class to play. After I'd unlocked everything I'd just role with that and the M14 rifle. Semi Auto rifles are just so satisfying to me.
one of my biggest disappointments with B3 is the limited nature of the all kit unlock-able weapons.
Shotguns are cool (870MCS is the gun I have most kills with in the game) and the SMG's are ok but there is nothing with a decent range thats not locked to a particular class.

Moving the medic duty over to assault seems like a mistake to me. I have zero motivation to play support now.
LMG's are only medium range, hugely inaccurate without bipod and have next to zero stopping power at anything over than close range.
Mortar is cool i suppose but re-supplying is dull and it feels as if your making very little contribution to the team to earn all those points.