I misunderstood then.
I agree with you that in general NVidia video cards have better support than Radeon. This applies to both gaming and the 3-D design applications that I use. As an example... if you look over the following chart less than half of the ATI cards listed are supported by autodesk software but nearly all of the NVidia cards are supported: http://download.autodesk.com/us/revit/revit_graphics_hardware_-_graphics_hardware_list_final.html