This review here should help you quite a bit
http://www.tomshardware.com/reviews/geforce-gtx-670-test-review,3217.html
Picking a graphics card can be a tough decision, but please don't get caught up in what one has the highest clock rates or best fps.
Thermal output, power draw, and noise are very important factors as well. The less power and heat the card makes the quieter it will be overall and the better it will overclock.
EVGA has solid warranty's on their products, and speaking from personal experience I've had good luck with ASUS and MSI when it came to hardware performance and replacement. EVGA needs to step up their game when it comes to cooling solutions in my opinion. Blower fans are nice when it comes to lower temperatures and heat exhaust, but once you start to stress the card the fan gets annoyingly loud.
If you have a decent case it will easily handle heat exhaust from the other cards blowing the air into the case and out of the back. EVGA cards attempt to push all of the heat out in 1 direction so the air has to travel the length of the card before it can escape but it puts less of it into the case itself. Ambient air around the card heats up as a result and the system begins to break down, the entire point of the blower is to prevent hot air from escaping into the case but the blower isn't efficient enough to do the job without being stupidly loud as a result.