I am using the latest drivers and they seem to be OK so far.
I have run CS, RTCW, Warcarft III and TW Shogun.
There is still some "blotchiness" on some things, like the default XP wallpaper. I don't really notice it though and I am not sure if it is any worse than anything else. I thought it was probably caused by the fact I am running a 1600x1200 display and there are errors scaling up.
It could also be caused if you are using 16 bit colour (check your display settings in the control panel).