I don't work in the space but my intuition tells me that the problems are mainly hardware related. These technologies have a lot of promise but are currently l

I don't work in the space but my intuition tells me that the problems are mainly hardware related. These technologies have a lot of promise but are currently limited by the state of the art. My personal opinion is that neither of these technologies will really take off until they are put into a stylish form factor - imagine a pair of ray-bans with embedded screens and chips that was nearly indistinguishable from the regular kind. Naturally, there are a lot of problems in the way of developing such a thing, including optics, miniaturization, durability, energy storage, etc.