All discussions of looks aside, isn't this a very weak joint in comparison to almost every other option. A miter joint without perpendicular anchors seems pointless.
Depends on the use case (; What I was playing with here was just a little enclosure to mount some electronics inside. Strength was not a factor. But clear, open sides and cosmetics were... For a more rigid version see: The Almost Perfect 3 Way Mitre (with Angle Corner Connectors)