I can't say for sure, but I believe the 8.1 drivers caused a major problem on my system. My system is only several weeks old, and everything was running perfectly. About 20 minutes after installing 8.1, my system would lock up from anywhere from 10 seconds to 10 minutes of being on. I would get the top 1/3 rd of the screen to get a black band across the screen, then all controls would freeze (even cntrl./alt/del didn't do anything. I tried a system restore but with no hope. To make a long story short, I had to wipe the hard drive and re-install Vista.....ERRRR!
Since the re-install, I've styed with the driver just before 8.1, and I'm too nervous to try running 8.1
I'm gonna stay with Cataylst 7.12 for some time.