I don't know, I had mixed experiences. Usually I have no issues with reference nVidia boards, but my non reference GTX 285 was a piece of crap. My reference 5770 and 5850 were even worse though, crashed at stock and grey screens, crashing when using hardware acceleration on flash. Only AMD cards that worked flawlessly were my old Diamond X1650 PRO and HD 4890. I'd say it's just bad luck along with the fact that there are a lot more high end/performance AMD cards that have non-reference crappy PCB designs.
Stick with reference/Lightning/Direct CU cards is my advice (even then there's no 100% guarantee that it will work flawlessly though).