I just finished it myself... that was abosolutely fantastic. I started in the afternoon and played it all day; I couldn't stop! I turned off the in-game Vsync (was a problem in the first one, not sure why it's still around, but it gets rid of the floaty controls and slightly laggy visuals), and forced it in the Nvidia CP, along with 32xAA, 16xAF, 8xSS; I spooged a little just watching it.
Visceral has a masterpiece here. The visuals are awesome; the effort spent on lighting and sound really shows itself. The puzzles aren't garbage. The controls are spot on (I don't see where there is to complain about using a M/K), after you get rid of the in-game Vsync.
The tech work is perfect. Kinesis and Stasis behave as they should. Physics works... as it should. No loading screens in sight (they did this on DS1 as well), along with good transitions. The horror portion of it is wonderful too; I'm not really into this genre, but Dead Space has kept it tasteful and engaging.
I don't understand how so many games, this far into the evolution of game design, fail in so many categories, and how so few can even come close to excelling in the areas that Dead Space 1 and 2 so seemingly effortlessly have... DS2 deserves a Game of the Year nomination. Mad props to Visceral!