I have no problems with the Nvidia 660 Ti as a performance card, but buying one from EVGA is not something I would do.
I'm currently running a 560 Ti that was manufactured by ASUS, and it runs quiet and cool(relative cool for a video card).
I wouldn't bother over clocking a 660 Ti at this point since there is no reason to (it already owns any game you might play it on) and in general, the 600 series cards are over kill at this point, next year they wont be though, so buying them now ensures you'll have a card that can play "any game" for a few years to come.
It isn't that I've heard anything specifically bad about EVGA, but my experience with ASUS has been so good over the years that I simply haven't had a reason to shop any where else. If ASUS makes it, I buy it from them, and it's been as simple as that for six of seven years now. Sometimes things malfunction, but they've always taken care of me. When they couldn't fix a laptop I owned, they gave me a free upgrade (The laptop I got back was roughly 2.5 times better than the one they couldn't fix).
The 660 ti is currently one of the best video cards in the world, and you will not be disappointed.
http://www.videocardbenchmark.net/high_end_gpus.html