I installed my copy this morning (I live above an independent games store and they often let me play games before they're released), and I agree with FastRedPonyCar completely, Crysis is amazing
The demo really doesn't demonstrate the level of detail that comes later on. The second level especially is head and shoulders above the first (which appeared in the demo). Tiny spoiler of one level: At the moment I'm possibly half way through the game, I just had a fight in an old misty graveyard in the middle of the night. You can punch or shoot the graves to reveal the skeletal remains inside
I'll post some screens soon...