I really wish people would do this first. I'm gonna make a post later tonight and hopefully somebody stickies it. Cause I find myself saying the same things over and over and over all the time. BENCHMARKS! If you guys wanna know whats gonna be better between nvidia and ATI, READ SOME BENCHMARKS. Here's the link I always refer to for them because they constantly update the cards to the most recent cards. and it goes really really far back.
I have the zotac 250 gts 512 ddr3 card and I was looking at the Sapphire Radeon HD 5670 Video Card. would this be better since its smaller or should I go with the nvidia 460?
I'm choosing my next GPU based upon 2 factors. One, as noted above, there's the highly-valued benchmark. Two, there's the power consumption of the card, which also may indicate heat and noise as well. It is harder to gather accurate info on power comsumption, but what I've seen online tends to give ATI cards an advantage in using fewer watts than Nvidia. Look at the charts on the bottom of this page: http://www.techpowerup.com/reviews/HIS/Radeon_HD_6970/2...
Also, I have known someone experienced with using both ATI and Nvidia cards, and he couldn't really recommend using one make over the other, performance-wise. Hence, for cards with similar benchmarks, you will probably get more for your money with ATI.