ATI or nVidia - The Unix Way

I have always been an ATI fan since nVidia did not exist. And so far it served well on my workstations. I don't even care that they are part of AMD now.
However, something that was annoying me for a while was ATI's driver which seems to not as good as nVidia's in *nix, especially for their newer and high-end cards. I am not sure why ATI does not care much about their non-windows drivers, but I am sure that they are loosing lots of faithful customers and a good market share for just the same reason.