texdiveguy:Yes same principle...just diff. approach. The biggest issue I have with a dual bladder system is in the event of damage that is caused to your primary...both bladders run a much higher risk of damage than 2 in a stacked system....plus as you pointed out when diving dry I don't have the stacked wing.
I see your point. And it makes sense. I mentioned in an earlier post that I have a singles wing...actually, it's a back-inflate bc (a Seaquaest Balance). So I am sort of stuck with buying a double-bladder wing, unless I want to buy two singles wings. Uhhh...I can't really afford that. Unles I can convince my daughter, who lives in Dallas, that daddy needs diving stuff more than she needs a trip to Holland.

Colliam7, I appreciate you feedback, as well. I can buy Dive Rite here about as cheap as in the States. I am looking at a couple of courses for alternatives. It's good to hear from people who use and have opinions over the items I am considering.
Best regards,
Phil