[ssewell]

There is a pretty significant difference between the expectations of a GameBoy screen, in which your focusing your fovea on the screen, and a visual projection in AR. The biggest issue with narrow FOV in this case is AR strives to make items appear as if they are in the real world. The moment you slightly turn your head and item is clipped by the projected FOV, yet you can still see the real world where the AR item "was", breaks the immersive illusion.

With VR, even a narrow FOV doesn't have this problem: As you rotate your head and a virtual item moves out of the FOV, it's simply clipped into blackness... no visual dissonance as you have with AR item vs. real world it lives within.

Edit to address the article: I think the fixed IPD is the real deal-breaker here. People have greatly varied IPDs. Some VR HMDs, such as the Oculus Rift, have a physical IPD adjustent. I don't see why the ML headset couldn't have this feature in the consumer version as well, though.