The resolution of these types of devices is a huge factor in whether or not I would find them acceptable to use, but the field of view they have is an even bigger factor. With very inexpensive monitors I can have a combined display that takes up a very large portion of my horizontal vision. I currently have three 24" monitors that give me a combined field of view of 123 degrees in their current configuration, with a 5760x1080 resolution also being a plus. Going to a VR headset with a FOV of only 90 degrees would be a step down as far as I'm concerned, and I would not take that step. The VR aspect of it, while cool in and of itself, would be a non-starter for me if the FOV was well below what I can do with monitors. Getting slightly bigger monitors, like 27" ones, would give me an even larger FOV, and alterations to their physical configuration can also change that FOV value and give me close to 180 degrees if I want.
As far as I'm concerned, if a VR headset isn't giving me something near/beyond a 180 degree FOV I really couldn't care less. I'd rather keep my head stationary and look at a display setup that does give me a larger FOV. Hopefully they get there soon, because everything else that goes along with the idea is pretty damn cool. But I don't want to look at an image where only a small portion of my vision is taken up. The immersiveness of a large horizontal FOV (vertical is less important to our vision, but would still be desirable) is too much to give up. I've lived with this setup for a couple years now, and wouldn't want to go without something similar/greater in FOV capability.