There was some show & tell about these, similar devices, and the Goldwing airbags at a DC public forum (basically a big discussion) on motorcycle safety last year. I attended parts of the forum & as an engineer I can see both sides of the arguments presented. Here's what I think it boils down to...
There are two things to protect against: deceleration (impact force) and abrasion/tearing. Most of what we wear for ATGATT is for abrasion/tearing, with hardening for localized deceleration and spreading of force at the point impacts of the knees, elbows, etc. It makes sense, because we seldom actually hit anything at a true 100% straight impact, which is a good thing.
The industry has the abrasion thing pretty well figured out and products from quality manufacturers have done an admirable job at protection. Unfortunately, it's easy to make inexpensive trash that looks nearly the same, using nylon that can melt to your skin, sewn with cotton thread that has little strength, in single stitching that will burst on impact. Buyer beware, you get what you pay for! Then there is the problem of shorty jackets and such that look good but which will slide up exposing soft stuff that you don't want exposed.
What these new & sometimes oddball products are aimed at is deceleration and somewhat at load spreading. In safety engineering, deceleration is defined as g-force over time. Basically, if you hit something like a concrete wall, there will be a really sharp deceleration over little time. Putting virtually anything on the surface of the wall to slow down your body's contact will cut the top off the spike in the deceleration plot. The Honda bag system is well thought out and there's at least one well-documented case about it working. When that bag's deployed, you suddenly have at least a couple feet of bag, plus, it's designed to changed your departure from the bike. (see the last paragraph) You also won't strike a single part of the bike as you depart, the size of the impact points between you and the bike are spread out reducing the force on any one point of where you contact.
Unfortunately, the jackets and vests seem to still be in the perpetual development stage. The Dainese system protects the neck/head/upper body, leaving the kidney, liver, & lower spine area exposed. Head & neck injuries are the worst, plus this recognizes how racers come off, so it appears this was what they were designing to help. Will it help on the street? That's a huge quesiton that the current big NHTSA safety study should help with a LOT.
The HitAir and others may give a little benefit, simply because they put something between you and whatever you hit. But again, they are something more to hook up and some look like they could be real problems in themselves, as far as heat in the summer. The inflatable vest over the best current ATGATT-wear probably is the best current combination, but it would be a pain to get on and ride with on a daily basis.
One last thought on the topic is about groin & lower body protection. This is the topic that people just don't think of, want to think of, or appreciate till hitting something. Most of the time, we riders don't actually hit something straight and go off the bike straight forward. We tend to lock a brake, lose traction in a turn, etc. HOWEVER, for those unfortunate enough to hit something more or less head-on, deceleration will throw your legs forward under the handlebars, as the rest of you goes over them. Think about where the family jewels are going in this event. Clue: your lower belly at least is going to drag with a lot of force in over the steering stem & instrument cluster area. You may regret having too securely mounted your electronics on a dash shelf & it's why windshields have the plastic screws. Obviously, the visual is pretty ugly and makes a good case for more rugged pants that have a smooth surface & are rugged enough to stay together, rather than splitting the crotch as they catch on the steering stem or something else.
