I'm trying to figure out what I want to do right now. I have a GTX 470 (w/Zalman VF3000F overclocked at 809/917/1618). It has served me well, but after crashing during the Battlefield 3 beta among other things such as Heaven Benchmark, I have to wonder. Should I upgrade? Before now, my overclock was very smooth at 829/937/1658, but now I am wondering if I went too far. I can't really test too much, since I am locked out of Steam right now. Is there another way to test for stability?
I am looking at the 2GB GTX 560ti right now and am wondering if it's a good choice ($270). If I got that, I would no doubt buy another once NVIDIA releases the 600 series down the line. I probably wouldn't overclock again, since I am not sure if I ruined a once $350 card in such a short amount of time. If my 470 is actually fine, then I would try to sell it since they go for about $170 on ebay.
If you did the job right when you swapped coolers then it should be ok but go ahead and scale back a little more. One thing you should do when it comes to overclocking never max out your cards for an extended period of time but find a good overclock that isn't going to degrade your cards. A gtx 560ti can come close to a gtx 570 but only when overclocked close to 1ghz. Only bother with one that has the mid plate.