I think you are comparing apples and oranges here. You should compare 4K to 2K or 30fps to 60fps, VR should be pitted against playing the game on your television. But 4K is the definition of an image whereas VR is a different way to play the game. So the best answer I could give you is, I'd rather play VR in 4K as being that close to a screen makes you see the individual dots much more than watching your TV whereas even on a 2K (1080p) TV you still can easily play a game without seeing pixels as you don't play with your face crushed on the TV screen.
At least that's my take on this. 







