I've been using Omega's drivers for my ati radeon 32mb DDR for a couple years now...
I've never really had any problems with anything not running, or glitches, or artifacts, or anything of the sort.
I guess that's kind of the point.
Also, Omega himself is very responsive to e-mail, which is nice. He's open to feedback/suggestions and quite willing to answer questions.
So I recommend them for ATI cards. Don't know about his NVIDIA drivers, I assume the situation is similar though.