lynx,..what you are saying about driver support is not really true any longer.
Both NVidia and ATI have had recent bone head drivers released. In driver support they are pretty equal today.
And if you only got 7500 3dmarks with the original 9700pro drivers then you had something seriously wrong with some other software component in your system. I had the original drivers and got over 12K, which has improved to 13K or so.
Every NVidia person who has moved to the 9700Pro had a lot of problems initially. All associated with not being able to clean out the old NVidia drivers. This is not uncommon in the video card industry, but I know if you have to be sure your NVidia drivers are gone, it requires a third party utility to do so.
I usually edit the registry manually when switching from or to either NVidia or ATI, due to this problem.