From the information I received on this forum and my own reading I think the 6870 in Cfx would be the best pick, with the 6950 a runner up.

I thought about an additional 5870 for Cfx but the wattage shot up pretty high. Plus the prices for an additional card seem to be going up as the supply diminishes. This might also be a problem later on should a card fail.

The 6950 looks good but uses a lot of power as well. Some of the reviews say it gets very loud and hot at 50 percent. While it has 2G memory, its performance increase isn't that much for what you pay in price, heat, and watts over a 6870.

The 6870, while a lesser card than the 5870, seems to do well in the Cfx config while temps, watts, and price are more reasonable.

Looking for some input before a final decision. This is what Newegg offers but not sure if there is any appreciable differences in one brand over the other.

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=6870

 

Looking at some of the links Tesla posted got me a little confused with some bench marks.

http://www.legitreviews.com/article/1080/10/

http://www.legitreviews.com/article/1488/6/

Reviewing the 5870 originally gave certain frames and info, but when compared to the 6950/70 in a later review, the information for the 5870 was completely different than the original review of the 5870. The differences in reviews are noted in game performance sections with the same game test.