With regret only 4 stars due to a small glitch which may not affect everyone and can relatively easily be overcome. The hot shoe has a spring loaded contact stud set in the base. Although this easily went on and came off some hot shoes on other devices, it was too big to allow it to fix on the camera for which it was intended (Panasonic GX7) without manually depressing it. Then it didn't want to come off again...
...without some force, which happily did no harm to camera or adapter. A closer look and comparison with a Pentax flash gun showed the adapter's stud to be wider, blunter, and probably longer than that on the Pentax, which was a rounded cone. (see photos with millimeter scale). A few minutes work with a small fine file amended the stud on the adapter, which now easily mounts/dismounts the camera.
I'm otherwise delighted with the adapter, but unless/until the stud shape is amended either by the manufacturer or customer, you should be aware that a little work may be necessary.