Microsoft and Unity are doing an amazing job building development tools for Windows Holographic devices like these (yes, I know today it's just HoloLens but these run the same tech just in a VR context). My concern is I've not seen any support for 3dof or 6dof tracked controllers in those dev tools, which means applications supporting those controllers could be dangerously late in arriving (I love Unity's integrated HoloLens simulator and debugger, but it took a long time after device release for that to hit release builds of the tooling)