I have a Hit-Air race vest, and had one of their standard models for a while. Never deployed in anger, but I did fire the standard one on my porch railing. It takes a pretty good yank to fire it. I have doubts about the story of a "kid" pulling it, unless you're using that word to refer to some a**hole teenage football player.
For me, the neck bracing is the big feature. The neck roll interfaces with the bottom of your helmet to provide pretty good C-spine protection. Think Leatt brace without it getting in the way when you're not in a crash situation. Same with your collarbone and ribs - protection that's just not practical to have there all the time. Also adds a fair amount of extra protection for your spine (I use a CE2 back protector anyway).
My one gripe is that the standard models put the cylinder and firing mechanism too low. It's fine if you're riding a cruiser or dirtbike (and maybe on a touerer/standard, depending on your gastank), but if your seating position is at all sporty, it'll be banging into and scratching your tank. IMO, it should be higher up on the chest or kinda diagonally mounted on your side.
It's about $500, which costs substantially less than a trauma team activation in the Emergency Department
.