I assume it will be sharper because it uses high quality optics which make all the difference, also it's native input isn't it? so no scaling that would soften the image.
This is why pro photographers spend thousands on a single lens. The work that goes into pro grade lenses is much more involving (using humans) than cheaper lenses which are produced using automation.
Fresnel lenses allow for thinner optics and use ridges (instead of a convex shape) to redirect the light back to your eyeball. That's why they are used for something attached to your head as they are lighter too but you lose light (from light scattering off the ridges). If you use more ridges to redirect more light towards your eyeball then you get a brighter image but lose sharpness so you have to find the sweet spot. I imagine Pimax have had a massive challenge getting these right.
The VRHero, I assume, uses standard optical lenses and would be the reason it weighs so much but the benefit is clarity, just like from a decent SLR lens.