I only got to play the first three missions at a friends, but they were very well done. Surprising large, there were a lot of ways to do things. Plus, the goal of Silent Assassin rank (get in, kill the target, get out, all without anyone knowing you were even there) is quite fun to try and attain.
Come next paycheck, I'll be shelling out the money for a new video card solely so I can play Hitman2.