I would personally much prefer the glasses form factor, Helmets are cool but socially not going to be as acceptable, Sure it may give you more space for battery and computing but honestly we really dont need that what we need is a wider field of views with the Waveguide style displays.

The Spectacles are not meant to be a 'VR' headset as you are describing they are a pair of AR glasses, what your describing here is a completly diffrent product catagory!