Some people assume that the AIR II is the octo you will give an OOA buddy. That's just not a good way to use it. You take the AIR II and give away your primary - make that clear with your buddy up front. Now the long hose folks are happy because it was always the assumption that your OOA buddy will TAKE your primary whether you offer it or not. I use an Oceanic Omega regulator so there is no 'right side up' problem with handing off the primary and my primary hose is short. My OOA buddy will have to stay close. But that's the way it was taught, way back when.
The only remaining issue revolves around trying to breathe from the AIR II while controlling your buoyancy (and your buddy's) with the BCD. This is clearly a much bigger problem in cold water than warm. To be honest, most of the dives on which I used the AIR II were in warm water. Buoyancy control was never much of a consideration. Basically, you have to remove the regulator from your mouth to vent the BCD and this MAY cause you to hold your breathe on ascent which is why you're venting in the first place. This one problem is probably sufficient reason to relegate the AIR II to warm water.
Some people will tell you the regulator is ineffective at depth. That is nonsense. Sure, it doesn't breathe as well as a high end regulator but I have used it at 113' with no problems whatsoever. In fact, I made it a practice to use it on every dive. Maybe not for a long period but for a minute or two. After all, I wanted to know that my backup was functional and effective.
If I am breathing from the AIR II for real, the assumption is that I am on my way to the surface. How good does it need to be? Remember: I'm recreational diver with no mandatory deco stops (this is a Basic SCUBA forum). If I were a deep diver or doing some other advanced technique, my gear would be somewhat different. And it probably wouldn't include a BCD in any event.
In cold water, I am beginning to think that the octo on a necklace is the way to go. You always know where it is! A long hose, or not, for the primary which you give to the OOA buddy. That frees up the inflator for the job of venting the wing on ascent.
But, choosing an AIR II is your choice. You can't expect every buddy you come across to understand its' function and there are too many varieties for the agencies to get involved with training. You should either be prepared to teach them or get rid of it.
Richard