I do not fully get the coincidence between stable drivers and open source drivers. I had several ati cards which had several problems with open source drivers. Even with open specs it does not mean that everything works. It is more a psychological aspect that somebody prefers open source.
I strongly believe that people working together in a community to solve problems do a better job supporting end users than corporations who tend to listen to their largest customers (other large corporations) instead. I don't use any proprietary software, but not out of principle. My favorite software just happens to be open source. (though we could use some more good games, I can only play wesnoth so many times )