They are pretty much the exact same thing, just with different branding.
I hear EVGA has one of the best warranty's out there, so that's a good thing to look at.
The Asus has the dual fans, which will provide better cooling, for better overclocking.
What about getting a faster card with less money ? The HD 6870 is faster than the standard GTX 560 and comparable with the GTX 560ti.
They are really close, only $3 CDN difference. EVGA has a lifetime warranty, so I'd go with EVGA. If you are worried about OC'ing I'd look around for data on how each OCs, but I suspect that they will be virtually identical.