What nVidia does do well is SLI, the scaling is so much better (from benchmarks I've seen) than CrossFire.
For low end, I was amazed at what I got from my little 9400GT. I bought it because it was the cheapest available at the time, and it certainly out-performed my expectations of a cheap card! (Until I forgot to plug the fan in).
But when I spent some money, I went straight over to the ATi camp.
Edit: what pisses me off though, is how much power a lot of these cards use at idle. My 9550 ran Windows Aero fine, and it had a baby heatsink and the fan had died, so it was passively cooled by a piece of metal with almost no fins on it (fins are so small I'd call them grooves). I was glad to see the 58x0's to drop their idle power, its totally unnessecary, and while it seems stupid, if the GT300 has really low (like better than 58x0 series) idle usage, I will actually get that.