I'd agree with the buddy breathing if I wasn't using my own gear. But the fact is that the majority of recreational divers are not taught buddy breathing anymore. It isn't in the PADI OW standards and requirements and isn't taught to PADI divers until training for Divemaster.
Yeah, Buddy breathing is an
optional skill on the OW course. I don't know any instructors who teach it - because having a proper AAS makes that requirement redundant.
Having a
compromise AIR2, makes buddy breathing a more valuable skills....and that is hardly a positive validation for AIR2 systems....
Each to their own... and if people like AIR2, then that is their choice. I've dealt with real OOA situations and, I personally, understand the value of simplicity and effectiveness under emergency situations. That makes AIR2 a non-consideration when I configure my equipment.
If, or when, the time comes that you have to donate your primary (struggle with an AIR2) to an OOA, stressed diver, in difficult water conditions..... you may also come to the same conclusions....
In my case admittedly my gear is a mix of recreational and tech gear but this is a configuration strictly used for recreational diving and if anyone cares, I do use a 5' hose on my primary second stage. I did my rescue training in this gear and am quite comfortable with it.
There is not such thing as 'tech gear'. It is true that technical divers use a pretty standardised configuration of equipment - but that does not mean it is equipment specifically for 'tech'.
BP/W is just another BCD style. It didn't originate in tech diving... but was adopted by most tech divers as the most secure method for carrying manifolded doubles...with the added benefits of stability, trim and robustness.
Long Hose is applicable to any diver who would wish to share air in an environment where side-by-side diver positioning may not be optimal. Traditionally this means overheard environments with restrictions - but it could equally apply to open-water environments if the diver concerned did not want to be 'on top off' the OOA reciever.