I think they are all equally good. Base your selection on clock speed and price. Mine had stock speeds of 520/1500 and I was able to oc it to 580/1550 useing coolbits. I got it for 269 after rebate.
The new evga with the model numbers starting with 580, are the newer ones that help take care of the memory heating problems that were causing all the artifacting in the earlier 7900's.