I guess different people had different experiences. My nVidia cards have worked just fine on Linux but my HD7750 ATI card does not work properly (random screen flashes and poor rendering) on Ubuntu no matter which driver I try.
Re:Nvidia PR Responds To Torvalds' Harsh Words
by JshWright on Tuesday June 19, 2012 @07:25PM
(#4134766)
> the majority of Radeon cards have full 2D/3D support in Open Source drivers (and those drivers actually have developers from ATI working on them)
And yet, the performance is still an order of magnitude worse than the proprietary driver (last time I bothered to compare them, anyway).
So, I'd still take ATI over nVidia due to ATI's much better Open Source drivers with some development done by ATI, though I'd take Intel over ATI for having entirely Open Source drivers with much more direct development from Intel.