I played with the large size version of Looking Glass at AR in Action conf this January at MIT. It's really cool, and the coolest part is the interaction is intuitive. You really can just touch a point on the hologram and have it react at that point.

As others have mentioned, it requires pushing quite a number of simultaneous views of the hologram through a hidpi display, the experienced resolution is not very high as a result and the holograms look a bit fuzzy.

It is right now probably the best out-of-the box way to interact with Holograms, especially in a shared environment. Hololens can't share holograms by default, and even if the app has implemented sharing, the holograms can't be touched. Meta glasses have some touchability thanks to their depth sensor, but again there's no easy shared way to interact with a hologram.

I think AR like Looking Glass is underrated, they were very smart to use natural interaction instead of gestures or a mouse/wand. That being said, I don't see it competing with AR glasses longterm.