If it's really that good, it seems like there's a strong case to make for buying one of these instead of a display panel upgrade. 3 quality 4k monitors is pretty pricey - and take up a lot of physical space when not in use, can't follow you anywhere, etc.
You can't really compare visual fidelity between VR headsets and flat panel monitors that way. The resolution is spread across your entire field of view. 4k per eye still good, but no where near what you'd expect from a 4k monitor sitting a few feet away.
