It is... niche. The display, in spite of butting up against your glasses, is still very small. You're not going to be programming on the command line with one of them (I've tried). It's also not really great as a secondary display either. At least for me, refocusing my eye on the vufine screen and back to the main display isn't faster than switching virtual desktops.

The applications where these do well generally involve large text or video... AR apps like navigation, or watching TV while traveling.