Hello all , ive been testing different driver setups ,and some minor hardware changes . My system is a AMD64 3400+ 754, 512 CL2 corsair ram, Audigy2, ATI X800 Pro
Level of detail set to full,  rest at default, 2XAA, 1280x1024, 512 Textures, Offline in tower on OZkansas at P1 
                      audigy2          /              onboard ac97
CAT 5.6 /         40fps               /            36fps 
CAT 5.5 /         39fps               /            33fps
CAT 4.12 /       45fps               /            41fps
OMEGA 4.12 /  47fps                /           42fps
Now ive overclocked the X800 pro to 520 core 560 memory from 475 /450
CAT 4.12 /       45fps         /          41fps
OMEGA 4.12/   47fps         /          42fps
Now im upping the cpu from 2400mhz to 2640mhz (12X 220), and setting X800 to stock 
CAT 4.12 /        52 fps          /       49fps
OMEGA 4.12/    54 fps          /       50fps  
So from what i see here there is a benefit from using my Audigy , but not as much as you may think , and that even with the 64 im still cpu limited in the game . I've also read alot of hype about the latest CAT release , and from what ive seen the 4.12's are still the best match for my system.  As always your milage may vary, i was doing this for myself , but figured id post what i found for the ati users out there   38