serambin:Suppose he keeps the octo and the pony, would that be a problem?
Reiterating, octos are a failure point with little benefit (from my humble perspective). Given he is buddy diving though, and only because of that, there are benefits to have a system that a buddy is familiar with. It could be argued I'm splitting hairs, but it sure doesn't seem so to me. I love h-valves (I outfitted my son with an h-valve): best of both worlds (twin second stages and full redundancy). I'm "sortof" frugal too: I would rather have more cheap but reliable regulators and an h-valve than a k-valve and a regulator with an octo but costing twice as much.
I, however, have virtually no buddy diving experience (although I did just get out of the pool with my son: he looks way cool wearing my double hose mistral).