It's a pretty bold claim to say 0% sickness as even old fashioned games can make a lot of people feel nausea[0].
[0] http://www.theguardian.com/lifeandstyle/2011/dec/19/video-ga...
[0] http://www.theguardian.com/lifeandstyle/2011/dec/19/video-ga...
Current video games make people sick for the exact same reason the Occulus makes people sick: they have you move with your thumbs, instead of walking around just like in real life. If a sufficiently good VR game don't give you a "move" button, but have you move for real instead, you can't get sick.
On the other hand, I expect sickness in simulator games even with a perceptually perfect VR system. Because, well… I used to fly (on a glider), and got airsick. I'd expect similar problems from a VR glider simulator, because… sickness is actually realistic in this case.