Far, far more usable. You’ve got a much wider FOV and much better head tracking (6DoF vs 3DoF) and that’s before the basic improvements you get from having more resolution to play with.
I thought there was no head tracking on XReal, but simply a 1-to-1 usage of the displays for video, i.e. without any simulated cinema environment around the movie. Which would mean the required FOV and resolution doesn't have to be as large as on a proper VR headset. Though it seems I was mistaken here.