Got my EVGA GTX570 superclocked a few weeks ago. Runs the game fine @ 1920x1080 with everything on max but epi off, except over London where buildings/forest detail needs to be dropped, but I don't think you'll be unhappy.
My last card was a Sapphire ATI 5770 and wouldn't run the game above medium settings well at all.
I know what your missus means about the price of 580, I couldn't justify the additional cost myself at the time.
So, happy new card!
