I think he's asking for what 660 ti has the better performance, the question here was a 660 ti.
There's several benchmarks that says the 660 ti is better, the overclock stuff not all the cards will overclock the same, some might even crash with just a bump in speeds.
@op, the asus has a custom cooling system with dual fan, which is better than a stock cooler, and it's really quiet, there's several reviews out there backing it up, that asus is the cheapest card 660 ti with free shipping and one of the best.
It's a good choice.