I don't have any knowledge so this is an useless node, but hey...
They said it "stimulates muscles by electric impulses". Now excuse me, but if it really does work that way, what makes it better than actual working out? Whether muscles stretch by impulses from brain or Gym Form Plus, you should lose energy, get tired and sweaty and all; only difference is whether you do it consciously or not.
So, it would seem to me that unlike what ad gives you impression of, using it is not just lying on couch and watching fat shrink, it's lying on couch and feeling as if you were jumping up and down, with muscles hurting like hell and god knows what (no, I haven't worked out, but so they say). That the ad mentioned that the technology's original use was to prevent athletes' muscles from slacking while they heal from broken bones or something.