It should be on par or faster in games that make proper use of SLI. In games like WoW, the 670 will be faster because WoW has piss poor SLI support.
I am going for this Cooler master storm stryker case corsair vs 650 psu Intel i5 3570k gtx 650 ti boost sli asus p8z77 v pro mb. Hows it
I have had no microstutter since 13.8 Beta 1 / 2. Skyrim loaded with all the STEP mods I had activated (very very high number). AMD don't need to fix microstutter...they fixed microstutter.