I agree with Switchback. I got a nvidia graphic card and last time i tried the driver wasn't optimized yet. Although I don't know if it's fixed yet.
To the game itself...well it doesn't look like so much was changed. I played Crysis 2 and - to be honest - I liked the graphics but that was all. Maybe I'm gonna watch some gameplays or whatever but I don't think I'm going to play Crysis 3.