I thought ATI were just as bad for the optimizations? I remember reading a lot about this when the HL2 DX9 (acronym hell) benchmarks were first out.
Content with my Ti4200 for now though it's getting a little long in the tooth, I'm holding on upgrading though, I generally tend to try to upgrade once every two generations or so, but I may be tempted to pick a 9800 pro when the newest cards come out and the inevitable price drop occurs.
Kinda dodgy about getting an ATI though because I still hear people who have ****loads of problems with the drivers and stuff, more so than I'm comfortable with at the moment.