Well if we're talking about todays motion controls and 3D, I'd take no load times easily.
But, I can imagine motion controls that do not suck and are responsive and extremely precise. Like a good FPS where you move on some kind of mat or a next gen camera that tracks your every movement and you're carrying a good gun controller. That is what it'll take to get me interested in motion controls and if that happened I would accept load times and would rather have motion controls.
As for 3D...meh. I'd take that I guess if I literally had a full 360 degrees of 3D goodness. I imagine something like a completely white room in the dark and then the game is projected somehow everywhere around you and you're almost literally in the game. Then I'd take the 3D.