I do agree with you @elleok. But, I think one of the practical uses of this device is those instances when the responder gets tired rendering the care. Having someone who can do the compression so you can focus on other things like establishing intravenous lines or advanced airway is a great help especially in critical situations. As for the CPR training, it is really recommended to personally train and not rely on any device because you know what, machines sometimes does not work.