I would surely go with XFX.
It has good Fans like Sapphire. You'll hardly see difference in temps between Those 2.
But the Main weapon here is the Lifetime Warranty. Who doesn't need that?
Lifetime warranty is pretty useless on a mid-lowend card. Its value as a gaming card would be nil in 3 years. Its a good card now, but in three years, not really.
XFX's cooler is crap and cannot be compared to Vapor-X. The only thing that beats the Vapor-X is the DCII, which is like $150 on newegg.
Sapphire FTW, I have two of their 7850's.