The best demo/test I've come across for this is Minecraft in VR for the Occulus Rift. It has a "theater"-mode, in which you can play Minecraft on a "big screen" in a room in VR. This mode works great for running around and doing things. And it has a first-person mode, which works great -- for standing
still and looking around. But I'm pretty sure the only people that can
play and walk/run around in first-person mode, are the 0.5% of US fighter pilots that don't get motion sickness at all.
I think it's a great way to demo the limits that motion sickness places on experiences for the vast majority of people. It's more than just being in control, and there are other effects at work, just like hand-held video footage without image stabilization is painful to look at. But my pet theory is that the big one is working with your body - if your body sits in a chair, your avatar should too (ie: drive a car, fly a spaceship is ok, walking around an art gallery at a leisure pace, not so much).