He said the GTX 560, not the GTX 560 Ti. Still more expensive but not nearly to the same degree.
2gb on an HD6870 is mostly pointless unless you will be crossfiring and using Eyefinity or a 2560x1600 monitor.
As for HD6850 vs HD6870 the HD6870 is 20% on average. Whether that is worth the extra money is up to you.
yea, the whole ti/no-ti thing is really confusing. Especially since most people mean the 560Ti when they say 560. Also, it doesn't help that whenever I try to find reviews on the 560 I only ever get reviews for the 560Ti and they call it a 560.
I got the 1Gb version since I can only run up to 1080p if I plugged it into my HDTV. Currently I'm on a 1680x1050 monitor.
The GTX 560(non-Ti) is basically equal to the HD6870 in performance. If you want one here's a review with a ton of benchmarks including a nice summary chart at the end; http://www.techpowerup.com/reviews/MSI/GTX_560_Twin_Fro...
The card in the review is OCed but it includes numbers for reference speed in all the benchmarks.