Considering the issue of crouching
So I watched your video on YouTube from the LockerGnome channel where you were playing HL2 with the Oculus Rift and noticed that you're strapped into a central ring which prevented you from being able to crouch down behind objects. Now I suppose it would be simple enough to use a button or some such but that would completely remove the sense of realism provided by this device. Have you ever considered mounting the central ring on a hydraulic piston of some kind? This could be tuned to provide enough resistance to keep a person from falling while still allowing a vertical motion to the prone position. I am not sure how walking prone would be on the device but it would at least be an explorable avenue for vertical movement. This would also open up the ability to jump, even leap forward since you'd be strapped in at the waist and wouldn't actually go anywhere. Something that bounced around in my head I thought might be useful. Let me know what you think.