We had a demo at our BMWMOA club meeting last Wed. I was the "dummy".
Wow. Inflates in the blink of an eye and is quite snug around the body. No movement possible of the head and neck for a good minute. I'd expect it to work well.
A bit heavy, not too bad though, but I would like to see some mesh somewhere. It blocked off most of the openings on my Vanson leather.
It was a He-Lite (light?) vest in hi-viz.