What are some alternatives?
When comparing VR Sketch and Oculus Medium, you can also consider the following products
Tilt Brush by Google - Paint in spaces around you with Virtual Reality
MasterpieceVR - Powerful VR sculpting & painting tool
A-Painter - Paint in VR in your Browser
SprayPrinter - Convert digital designs into wall art from your smartphone
Poly by Google - Explore the world of 3D
Quill by Story Studio - Paint in virtual reality on an infinitely scalable canvas