HardOCP takes another look at Crysis to see if DirectX 10 delivers on its promises:
The questions are: Should you be playing Crysis in DX9 and therefore should we be testing in DX9 too? Or does DX10 truly offer a better gaming experience as has been touted and pushed since DX10’s introduction? To find the answer to these questions we will be using the fastest single GPU video card available at the time of evaluation, the NVIDIA GeForce 8800 GTX, as well as the newer and almost as fast NVIDIA GeForce 8800 GTS 512MB. On the AMD side we will be using ATI’s multi GPU video card the Radeon HD 3870 X2, and finally ATI’s fastest current generation single GPU card the Radeon HD 3870. These combinations will allow us to look at single and multi-GPU performance in Crysis DX9 and DX10. Unfortunately the GeForce 9800 GX2 did not make it in time for this evaluation.
Check it out over here. The reporter writes there were some image quality differences but these were very slight and didn't really change the gameplay experience. If you have an ATI card he recommends to run in DX9 so you don't suffer a performance hit but with NVIDIA cards it doesn't really matter as there's no difference in performance.