On Arch Linux using the:
SigLevel = Optional
Server = http://pkgbuild.com/~lcarlier/$repo/$arch

repo built from GIT, which also has vulkan-radeon-git (from https://github.com/airlied/mesa/tree/semi-interesting) and vulkan-intel-git is currently rendering things on my RX 470 with the vkdemos from (https://github.com/SaschaWillems/Vulkan)

I am sadly unable to include screenshots, but most of the demos that use textures are badly distorted, and some (displacement and tessellation) crashed my machine.