I currently use an X1950 Pro in my main Phenom II machine, but I don't know if that's old enough to be called vintage. I've had better results on old games on it than on DX10/11 hardware, but I don't know if some good DX10 card with old drivers would offer equal compability and better performance to boot. It runs a lot of stuff fine in 1920x1080 but whether AA works or not can be hit or miss due to flaky drivers. Would be nice if there was some initiative to find a sweet spot in terms of hardware and drivers as a compromise between compatiblity for old and performance for newer games...
I'm using the newest Catalyst (9.3, 10.2 or whatever it was) on XP. To give one example where that card is beneficial, touchy D3D Outlaws runs fine on it. The real caveat with these ATi drivers is how they don't let you customize settings for each game (except for some silly profiles), which I believe they fixed with the newer revisions, but didn't bother to bring it to some "obsolete" cards..