Good question, I say... I have the DK2 and I don't have the nvidia card in my macbook. It runs... ok, but is really an issue with heavier games/demos. Dropping frames with VR is a huge problem if you get dizzy at all - it makes it a lot worse.
Sure, but you have several things working against you. Integrated graphics aren't gonna be great for even non-VR applications if they're graphically demanding. And you're running 1) a laptop, and 2) a Macbook so you've got something that is much more geared toward lower power usage and (in the case of most Apple notebooks) thinness and lightness so those power tradeoffs may be more pronounced.
Honestly, I'm impressed you've been able to do a whole lot with it at all. I've got a fairly decent laptop (i7, 16GB RAM, and a mediocre nVidia 760m GPU) and it's still been underwhelming when I hooked the Rift up to it.
Desktop will be much more power for the buck this early in the game. Portable will catch up but you sacrifice some bang for the buck when you get something more optimized for portability and battery life.
