It only works with spider platform systems aka 790x.
It loads up my CCC overclock profile, and can load your overdrive profile (I dont use it tho), and cuts out a large list of vista services. It really reduces the ram footprint of the OS by a huge chunk, and effectively speeds up your system a bit. It also enables a couple of 790x tricks, I'm not exactly sure what.
I don't know what the fps gains would be, if any, but it's more just to provide a quick button to kill all the 'crap' processes that are always running.
The only downside is that it can't always bring things back perfectly when you turn it off. Sometimes the aero interface comes back, sometimes not. Sometimes a reboot is necessary afterwards to bring everything back to normal. I tend to use it mostly when benching.