On D-Air suits, the system has a self-diagnostic check when it's turned on (by snapping the top buckle on the suit) and the LED indicators on the right arm of the suit will flash green if the system is good to go. Once the airbag is inflated in a crash, the suit needs to go back to the Dainese repair center in California to get a new bag and gas cyclinder installed, which costs about $250.
Regarding Kangaroo vs Cowhide suits, much of what was said above is true, Kangaroo is thinner for the same level of abrasion resistance as cowhide, so therefore a Kangaroo suit is lighter at the same level of abrasion resistance. Kangaroo is not "more" abrasion resistant than cowhide when it comes to a suit as a whole, it's just at the same level of abrasion resistance the kangaroo can be thinner. The big downside to Kangaroo is it has very little stretchability, which has a couple of negative implications. One is that if the suit doesn't fit perfectly, espeically if it's a little tight in one dimension or another, it will be very uncomfortable and won't "stretch to fit" like a cowhide suit generally will. The other is that if the suit doesn't fit perfectly, generally it will have to be larger rather than smaller since smaller won't stretch, and with it being larger than optimal the fabric is more likely to fold over and in a crash can be torn more easily. For the MotoGP guys, who get custom-tailored suits, Kangaroo is a perfect solution. For "off the rack", depends on how well it fits you.
There are of course many different quality levels with any kind of leather, and that can impact things significantly as well.
We started carrying the D-Air suits earlier this year and just had our first crash tester last weekend at a race. 100+ MPH lowside in the fastest turn at Motorsports Park Hastings, bike and rider slid of, hit the dirt and both tumbled several hundred feet out into runoff area. Bike was pretty much a yard sale of an S1000RR. Rider has a sprained left knee and otherwise no injuries. The airbag went off of course, and knowing others who have crashed in that same spot on the track over the years, I'm confident that suit saved significant injuries to colar bones and shoulders. No one comes out unscathed from a race pace crash in Turn 3, this is the first time I can recall, I'm very impressed with D-Air!
Regarding the A* system, I saw a direct comparison of it vs. D-Air when I attended the D-Air training this Spring. Granted, it was put on by Dainese so obviously biased, but the significant design differences between the D-Air and the A* were glaringly obvious and I'd have WAY more confidence in D-Air than anything else on the market. Dainese did this one right, tested for 8 years in world-championship level racing, so it's well-proven. The only opponents to the system are probably orthopedic surgeons! Ha ha!
