Update:

This still hasn't completely solved my issue. I get perfect FPS, 60+ on main and 30+ on the alts... But in LBRS when I'm mouselooking it stutters for a second or so now and then. I've no clue what to do since I bottomed out the graphics.

I'm running an Athlon 4800+ dual core, 4 gigs of Kingston, 8800GT overclocked.