regarding taking them off being an issue, I would presume eventually we'll have headsets you can flip up, like those flip up sunglasses people sometimes have.
http://technical-illusions.myshopify.com/collections/frontpa...
If it can deliver on the low-distortion, it has a major advantage over Oculus. The distortion correction for the Rift currently requires you draw to an intermediary render target about 1.5X the resolution of the screen. This throws away a lot of pixels and has a huge performance penalty, and the geometry-shader approaches to avoiding the penalty that were attempted so far haven't worked out.