Im running 2 x GTX690's in SLI with an Intel Core i7 3960X and the performance is staggering. Yes I know this will be seen as total overkill but my logic is supported by the fact that I have just replaced my Dell XPS720H2C after five years of fantastic service which at the time of purchase was also overkill.
At Jackson Hole in FTX with all sliders at max including 100% traffic in a Carenado C208B with hires textures I have over 60 FPS. In the air this rises to >150FPS. I
know that such FPS are meaningless in terms of what you see but in terms of smoothness and fluidity, its a whole new sim.
However I was nearly very disappointed when I first fired up the new system. Initially I had severe pauses and stutters and for a moment began to think how stupid I'd been. It was only when I read Robert McDonald's excellent review of the card that I realised I should turnoff vsync, the improvement was instant, so a huge thanks to Robert.
Regards
Adrian