Comment Personal experience (Score 1) 212
For me, out of nVidia and ATI proprietary drivers under linux, ATI's were always more problematic, especially under 64 bit Ubuntu.
Every couple years I try to get an ATI card and make linux work with it and every time I get very frustrated (last one was 5830 card in 2010). Yes, I don't have much expertise in kernel hacking, but I don't expect that I have to do that much tweaking to install a freaking driver. So far nVidia never presented a problem under Ubuntu. It might re-compile itself, but that's as bad as it gets. The amount of trial and error for ATI is waaay worse (how on earth can "official" binary driver complain about unsupported hardware? open driver being so slow you can see windows painting? yuk)
So, for me, out of two evils, the lesser one is nVidia. Maybe it's almost time to try a new ATI card yet again