Bah! It's coke and pepsi. People who like the brand they use will attack the other brand with no justification. INVIDIA tends to run better in OpenGL, ATI tends to run better for DirectX. ATI updates their drivers every month, with nice customization control panels. Many card makers provide overclocking utilities.
Considering the 9600 PRO is an "EZ" (why do they need to keep adding suffixes?), I'd consider the 9800, but overall, they perform about the same. I'm in a similar situation, deciding which new card to buy. I'm torn between a 9600 XT or 9800 (non SE). If I could find a 9700 or 9500, I would probably buy one. They are both better than the 9600.
Too many products!!!!