What resolution are you playing on? Vista or XP?
1680x1050. Vista 32bit. 8800GTS 640mb. (OC:626/1457/971)
I notice no visual difference between Dx9 and Dx10.
But dx10 takes a big hardware hit.
I hit a max of 60fps on the beach.
This just made the game alot more fun.
I can actually play the last level now without having 8fps.