Drivers still arento 100% reliable but they've made dramatic improvements, and their getting pretty good. Most users don't seem to be having any problems at all with them, though I've heard one or two say their still having a few problems.
Performance wise, the Retail 8500 performs a notch below of GF3 Ti500, though it's other benefits and cheaper price tend to off-set that for many people.
It's quite a bit faster then the Ti200.
The OEM 8500 performs about mid-way between the Ti200 and Ti500.
The AIW 8500 performs about equal to the GF3 Ti200.
ATi's improved the performance a bit with each of their last couple driver releases, so one has reason to hope for future performance improvements too.
Overall, I have no qualms about recommending the 8500 anymore.