KCDiver, look at what you are saying. You claim you don't like the AIRII because it isn't redundant. Yet, even though Scubapro offers the octopus, etc as alternatives, you ignore that and blame the company for selling an extremely innovative product designed to simplify the diver's kit. You base your complaint on your own definition of safety which is rubbish. If that thing was unsafe, the manufacturer would have dropped it like a hot potato.
One thing I remember, Scubapro was the first to offer the vest type BC when the norm was the horsecollar. US Divers had been offered the design first and they turned it down. Later, they had to scramble with inferior substitutes. To wit, while the competition was trying to figure out how to expell air from their bulky double bag designs, Scubapro made a TOUGH, compact, single bag construction with flow through aircell.
Scubapro was the first to offer a balanced second stage.
That is one more example of a history of innovative products. The quality of Scubapro products is the highest in the industry. As far as cost, shop around. Scubapro products are so ubiquitous, worldwide, they show up on EBay and such places for discount prices, brand new.