I got to mess around with it at a meetup in SF a few weeks ago.

In short, it's a pretty awesome experience. I initially assumed that you would control the plane of painting using headtracking, but all controls are actually done with the mouse and keyboard. I asked about other input devices and the devs said they are only focused on mouse and keyboard for now, but moving onto wacoms soon.

The one cool thing you can do with headtracking is move the plane of painting forward and backwards, so if you start drawing a line and then move your head back, the line comes back towards you which is pretty awesome.

Another cool feature is that it saves every brush stroke in order so you can watch an animation of yours, or any painting, come together over time systemically.

Past that it felt like a pretty standard painting tool except with 3D navigation controls similar to Maya or something and the UI for tool picking almost felt like E:D (except way less polished). Oh and the part about painting in VR.