Air bag vest discussion

I've decided to buy one of those air bag vests, and I figured I'd mention it here for discussion.

First, there's some that come in jackets, and some that can go under jackets. The latter seem to require the same brand of jacket to work reliably, and I don't particularly care for either type. So my research has been entirely on vests that can be added to any riding gear.

Second, there are 2 ways to deploy them. Electronically, with speed and attitude sensors, or mechanically, with basically a pull cord. The e-versions are expensive, almost twice as much.

So- what do people think about these vests for a monkey? I don't think any of their algorithms are tuned to work the e-vests, so they're out. The mechanical versions require you leave the bike before they deploy. Will a monkey be ejected in most crashes? What sort of trauma would be expected, it would be way different from a rider. I can't even think of where to look for that sort of info.

For my choice, I found the top 2 brands were HitAir, and Helite. They're both pretty similar, with Helite being slightly better and more expensive. The one deciding factor was that hit air had a gap between the neck and back, from about the first thoracic vertebra to about the 10th or 12th. I broke my back in two places, and I have a fusion from the 4th to the 10th, right where there is no coverage, and decided to go with the Helite. I certainly don't want the 'hinge' caused by no support, to be where I cannot bend without major troubles. Helite also deploys slightly faster, but when we're talking increments of .01 seconds I'm not sure it matters much.