I'm in New Jersey, where the viz ain't good much of the time. Since it's so easy to lose sight of your buddy, many divers here use pony tanks for self-rescue. I'm looking at the Aquavit system and am wondering if anyone here has actually used one.

One thing I read indicated that it's too easy to breathe down the 6cf bottle at depth, that the main tank's first stage high-pressure port can't keep up and that could make air sharing dicey. As a result, I'm considering the next larger size bottle. Comments?