I found using the Thompson was very accurate, it did/does take practice and 1337 skills that I posess to master the gun's iron sights. I almost never use the crosshairs now, and go straight for the head. That takes practice too. The leaning thing is very intuitive, and I'm happy to say this is the first console-PC game from EA that actually looks like the dev did keep PC Gamers in mind.
I just had some crazy cinematic moments, I was on the roof, picking away at targets on the ground, the ragdoll physics is great, the lighting is where the UE3 really shines (no pun intended). Anyway, I was on roof, blasting away with my M1 Garand, I ran out of ammo, and then started shooting away with the Thompson (using the iron sights of course) and then I ran out of ammo...these guys just kept coming, and my team mates were all getting killed ( I love how its not like CoD2, where if your teammates die, more come right off the bat) and so they were all shooting at me, the sounds were great, plaster and tile was getting chipped away from under me, I felt my ball sack might get ripped away any minute. Absolutely stunning, they were running from that blazingly lit alleyway, the light reflecting off their German-borrowed stormtrooper helmets and screaming obscenities at me in Italian.
it was fucking pwnage.
And btw, its quite possible to shoot accurately with the Thompson; use iron sights, aim, fire in bursts. Nice elongated bursts, but not to where it becomes a hose fest.