I would say, it is best to just play on pc. Unless your pc isn't that great. But are you talking about if you put in too many hours into your game, that the framerate starts to drag? I think its usually after like 50 or so hours, the framerate starts to drag. They addressed it kindof. But it certainly isn't 100% fixed.
I'm not expecting a rock solid frame rate, I never did on a game THAT big, but if it no longer plays like a flipbook, I consider it fixed.