The acid test...
...for me, anyway, would be the ability to use the VR device while seated in a physical 'cockpit' , which could be for a bicycle, motorbike, racing car, glider, jet, sailing dingy... which is fitted with the appropriate physical seating, harness, controls and instrument panel and have the VR device provide 360 degree external scenery without obscuring any of the controls or the cockpit interior.
If it can do this, and I don't mind at all if it needs special paint, etc. to delimit cockpit/controls/instruments which must not be obscured, then I want one and so will flying and driving schools.
If it can't, then it goes in the MEH! bin because it can't begin to compete with a properly set up conventional simulator with 360 degree screens and scenery projectors, and so will be useless for realistic simulation in driving or flying games and no use for teaching flying, driving or other physical skills.