Well I've got an AIW Radeon under Win2k. The release drivers were stable to a point. After capturing say 20 times, I would get to a point where the capture would seem to hang. Ending the process via task manager, would give about 5 seconds before a blue screen.
I'm using the 3116 drivers and they seem to be rocksolid. Haven't had an ATI-induced crash since I installed them. The biggest file I recorded was 7GB in size, 480x480 MPEG-2 (IBP frames, 100% motion compensation) no dropped frames. I can't capture any higher than that using IBP frames without dropping frames.
Overall I'm quite happy. I was having an issue with static audio caused by my Asus CUV4X (there is an issue between the ATI software, this mobo and an SBLive). But removing the ATI DVD player solved this problem and the audio is crystal clear.
-GL