Speaking of xtal we can see that it is not so much the resolution but how the lenses are designed,
in few words less deformation of the lenses= clearer image. Surely having good lenses makes the cost go up a lot, especially if they remove chromatic aberration.
I would like the next hmd to be similar to xtal, made intelligently and with little deformation of the lenses and the image, a screen with nice colors and foveated rendering.