I recall seeing a similar product @ 10 years ago, air powered. In essence, the training cartridge was the world's smallest airgun - the case contained a small air reservoir and the valve was controlled by a release button in the "primer pocket". The gun's firing pin tripped the release. The bullet was a plastic cup.
It was a neat idea, but the cost was astronomical. "Cartridges" were $30 to $40 each [they were precision machined mini-airguns, remember] and the associated compressor was at least a couple of hundred more. So 12 rounds of .38 would cost $450 or so, two magazines for an M-9 or Glock PLUS the barrel/slide conversion kit would cost "Oh, HELL NO!!!" (<--- Typical Chief's response)
AirSoft is far more reasonable for force on force training, IMHO, and if you want to go a step up, there are always quality pellet gun replicas to use for initial or periodic marksmanship training. And casual plinking sessions.
I am a great believer in being familiar with your service pistol. I am also a great believer in the KISS principal, both from an operational and management perspective. Just as fisherman's lures are designed to catch fishermen, I see these expensive gizmos as intended to catch the uninitiated.