ATI was a low budget mass-market cheapie company before NVidia was even formed. Only when NVidia ate 3dfx and had no competition did ATI see a market ripe to pluck. The last batch of ATI cards may have been faster in some games, but their drivers were very iffy depending on what OS and what games you were playing. For Linux, don't even think about it. Their driver development for Linux can be listed under MIA.

I liked 3dfx (I even had a 5500) and was mighty pissed when the Nvidia assault brought them down. However, they have some very decent drivers across multiple platforms and I can get a game without a single though as to if I will need to switch drivers just to suit it.

Unless Matrox gets on the ball, I'll still be sticking with NV cards for my machines.