Hello Matt65,
I have not comunicated with you lately; I hope things are going well.
I thought about buying the spare air system. But, they don’t hold enough air to do a safe and slow ascent from depth. It is a great system to use if you know your buddy is somewhat close so that you can use his octo for the safety stop.
My 6 cubic foot pony is "just" big enough. I always dive with the valve off as I don’t want to lose any air because of it’s small size. Free flows do happen. I have the valve postioned where I can get to it quickly in case of an emergency. When I have practiced pony bottle ascents, I usually spit out my primary reg and then exhale all of my air so as to simulate an actual emergency, then I turn on the valve and grab the pony’s second stage.
markm