I assure you, apart of "nvidia is better, ati is better stuff" they both are awesome at what they do. That being said, I, just like you, changed from nvidia 9800gtx, to ati hd 5870. What can I say, I'm loving the card....super low temps at idle with stock rates and fan.. not passing from 70º at full load(can't notice the fan at all, I could lower the temps more if I wanted to, at 50% of fan I hear it but not very loud), low power consumption.... The video options for movies, avi files etc.. It's awesome, I liked that the best, since I own a samsung monitor and magictune do not work under win7 yet. The only thing I miss, is the nvidia program control. Even when ati can do it too, it has less options plus you have to change profiles, but it's no biggie. Another thing to have at count with Ati 5xxx series at win7 is the vsync! It does not work unless you force it with rivatuner or so.. Off that, lots of ppl are getting hd 5870's, I wonder how good nvidia is still doing, and I want to see the next cards soon, both nvidia and ati!