FWIW I am not a fanboy. I used to use XFX back when they had double-lifetime warranties. But for my mining rigs I went with two systems, each with 3 Gigabyte 7970s, the GV-R797OC-3GD model. I haven't tried to push them too far, but I have gotten about 700 kh/s scrypt, and 620 MH/s SHA256. They are voltage locked unfortunately, but I can OC memory for scrypt, and UC memory for SHA256 while OC'ing the core just fine.

They are in a milk carton open air case with 250mm fans blowing at them, and they run around 65C with 24C ambient temps.