I'm using a GTX 580 and I've been having some minor issues. Granted, I'm using a few texture mods, but I would think my FPS should always be near 60. (i've got an i7 2600K cpu)
In fact, I was installing some mods for my friend yesterday, and he seemed to have the same performance level as I do, if not slightly better. The main problem being, when I look around quickly the game lags a bit. He is using a GTX 400 series card, not sure which one though.
I guess to answer your question succinctly, no, I've not had any real problems with my 580 card.