The MSI GTX 560 Twin Frozr is factory overclocked so it is significantly faster than the reference model shown in those benchmark comparisons. The 6850 benchmarks were also famously pumped up at the expense of image quality in what some refer to as a benchmarking "cheat". So in the real world, the MSI GTX 560 benchmark should be higher, and the 6850 benchmark should be lower than what was shown in that link. http://www.guru3d.com/article/exploring-ati-image-quali...
However, the specific gpus on those newegg links, the 6850 seems to have better specs (But I'm not an expert on these things as you can tell).
Which one would be best for me? Thanks.
(also why did they slash $70 off of the 470? something wrong? I also noticed that the 470 has a low core clock. Is that bad? What is the difference between opengl 3.2 and 4.1?)
That GTX 470 is cheaper because it is a recertified model, i.e. used.
You need to figure out your budget, then get the card that fits. If you can afford the GTX 560, then it will definitely be worth it. If not, aim for something cheaper but also at a lower performance point.
A chart showing relative performance proves that, even for your resolution, the GTX 560 will deliver significantly more performance. As the chart below shows, 30% more on average. If you play demanding games, or are looking to get some of the new releases this year, you will be glad you went with the higher performing card.