bassfisher, I hope you enjoy your new card. I recently made the switch from Nvidia to ATI by purchasing an HIS Radeon 5870. I'm very happy with it -- the performance is fantastic. I will admit I ran into a few minor problems, but I've been able to find solutions, so in the end nothing is really preventing me from doing the gaming that I want to do. I also have to commend AMD/ATI for being on the ball as far as updating the drivers -- they just came out with a new release that solved an issue I was having where my monitor would not go to sleep, so it's nice to know that they seem to be aware of the difficulties their customers are experiencing.
It's not like I hate Nvidia or anything like that ... I think I just wanted to see what kind of luck I would have with a different brand. The price on the 5870, along with other factors like DirectX 11 capability and the fact that it came with DiRT 2, sealed the deal for me. I've been with Nvidia ever since I had a GeForce 2 ... although for the most part they worked fine, I had my share of problems, too. I don't know if this means that I'm always going to buy ATI video boards from now on, but at this point I think I can safely say that I at least know that I can go either way, and that other options besides Nvidia can work out just as well for me. (I bought an HP notebook last year that has an ATI 4530, and it runs older games really well.)