I haven't had any drastic problems like everyone else (except for weird and sudden system crashes), but I've had frequent system "hick-ups" like every second. Sure I'm being picky, but if you have to run across telos station and the framerate moves from 50+ to 5(or less) all the time; you'd be annoyed too.
I really enjoyed the polish of the first game, and it's been very dissapointing playing this one.
Hopefully the next patch will stabilize the game more...if it ever comes out.