I am a hardcore MC VR player and I love what is coming up BUT 

I have found that when swimming in VR and being underneath blocks a black box appears that completely blinds you in blackness can't say how annoying it is to loose everything in water because of a visual glitch

on the other hand when switching the experimental caves and cliffs option

ive allso found a less horrible visual bug

when I mine below Y 0 my items in my hands vanish, I can still use them as normal just can't see them but the black boxes dissapare aswell