Right from the launch of the Catalyst 9.3 drivers, things weren't looking good with many people complaining about issues they had with the driver suite. We had two major problems; for the most part performance was down and the only time we saw performance being up was in Left 4 Dead using the HD 4870 X2 at the lower resolution. This is in line with the promise of performance improvements for CPU limited games.
The other issue we had was that as soon as we installed the driver on Windows XP with the HD 4850, we couldn't run any 3D applications. Loading one would cause our system to simply reboot.
It's clear, though, that by looking around at forums we're hardly the only person having issues with the driver. This will be the first time that we won't be using the new driver on cards that come in and will simply stick to the 9.2s.
Hopefully you have more luck with them, but for the most part we would recommend that you avoid this driver. The only other people who seem to be having some luck with this driver are users of Windows 7. With AMD taking the time to focus on the new operating system, it could mean that XP and Vista users are not going to get the attention they were up till now.