http://enthusiast.hardocp.com/articl...50aHVzaWFzdA==

Shows you that you can have WAY BETTER textures with way more realistic lighting without much performance drop.
In fact, if you run the game under DX10 to make it look like DX9.0c, performance is better than DX9.0c.

This reflects what Crytek has been saying: That Crysis runs better under Vista and DX10 than DX9.0c.