Tiltbrush on the Vive is friggin amazing. The thing with it is that it's not just a painting app. If the brush width is set to wide and style to solid it's the most fluid and intuitive 3D modeling system I've ever used.

I'm a hobbyist artist - using the Vive for a first time I could sculpt a 3d figure, life sized, in front of me in just minutes. (Professinal 3D designers are probably faster than that on their 3D system of choice but I'm just an accidental hobbyist).

I would guess the better one can generate shapes from memory the more amazing the experience is.

This will be huge with designers.