1) In order for an air donation device to work properly it requires knowledge at two ends, the donor as well as the receiver. This device changes air-share protocols and most students in their open-water course are never trained how to use this. Atomic makes similar contraption called Atomic SafeSecond inflator.
Atomic Safe Second Inflator (SS1), Stainless Steel
You will notice that this has a cuter, brightly colored second stage which is built into the inflator. During one of my dives a whjile ago I was buddied up with an insta-buddy who ran very low on air during our safety stop. He requested air by showing me his gauge that he was low so I gave my octo to him. He was extremely out of shape and probably had some medical problems (or maybe just anxiety) so when I gave him my second, he started breathing down my air really fast like he was out of breath. We were bobbing 15 feet from the surface so none of us were in danger but he was breathing so hard and heavy that I was concerned if he is having a heart attack. Then another couple showed up at the safety stop where we were holding the rope and we were not alone. I showed him my own air on SPG which was pretty low just so that we are both aware that I am also running low now. He took that gesture to mean that I did not want to share air anymore!!! In a total state of panic he took his own reg in his mouth and went looking for someone else on the hang rope to share air with. Now keep in mind that this was a safety stop and he could have made it to the surface and would probably be just fine but he wanted to complete whatever few seconds of time his computer was showing him and he wanted to borrow air from someone else. The couple next to us had just arrived at the safety stop and did not know that there was a low-on-air diver being insistent upon not surfacing until he has finished his computer generated stop time. He swam to the woman, grabbed her SafeSecond octo/inflator and tried to put it in his own mouth! I don't know whether he looked at it and mistook it to be a dangling octo since it was the closest thing on her that resembled a real octo. It is also possible that he had never seen that contraption in his life so he did not know that he was supposed to ask for the reg in the woman's mouth and not her inflator/combo. May be he did not want a reg to go from mouth to mouth so he decided at that very last minute that he will breath from the inflator instead of the primary user. In any case, he took her inflator second in his own mouth wanting to breath from it. She was looking at him totally confused like "Dude what are you doing?" and neither of them had the luxury to engage in the conversation we are having right now. Her husband / boyfriend realized that he needed air and then proceeded to donate his own octo which was a regular one (thank god) so they were on the same page as to how it was supposed to be used. Now this was not a dangerous situation for anyone at any point but it did cause unnecessary confusion which could have been avoided if everyone just had a regular octo. Bottom line is that while you may be competent in donating, the donor may not be competent in receiving. People are not trained on this as part of their open water course and they may have some very bizarre ideas on how it is supposed to be used. When they execute those ideas under water, a conversation will not be possible.
2) Millions of dives have been done where the device was never deployed for its intended purpose. In times when it is needed to be used, I think everyone will agree that it is not the quickest easiest and the most optimum set-up required for the job.
3) The bigger question here is why not a proper second stage? How much money are we going to save by purchasing this gadget instead of a proper second stage? This is an expensive hobby and we are saving no more than a hundred bucks. Is it that much of an advantage? As for second stage dangling, there are plenty of solutions that can address that so why not look into those?
