Thank you for the video, very instructive. Like all similar less-than-lethal weapons surely it has its merits but also some drawbacks. Biggest drawback is imho that it is very difficult to predict the effects of the shot. Such impact weapons use energy transfer without penetrating the body (I hope so), so the effect is very much related to pain perception, which can be effected by thickness of clothes, drugs or determined will. Better to have than nothing perhaps.
BTW, what is the energy density of the projectiles at muzzle velocity?