Some of us feel that an STA is an integral part of our rig. All set ups have them in one form or another. I prefer the tried and true single metal adapter. IMHO, its advantages far outweigh its disadvantages.
Given the OP's 'handle', I would guess that he plans on buying Halcyon gear. If so, I believe that he would be WAY better off using an STA. The Eclipse model has always required one and the the Pioneers work MUCH better with a standard STA. I'm not sure but I believe the latest Pioneers have changed and also require an STA. Perrone... what's the deal with the latest line of Pioneers?
If he buys a different product, then he's gonna have to petition Netdoc for a new name!
And... I can't let this one go either... "An STA just puts the tank further from your back." Huh??? We're talking 3/8"... less than half an inch! That has absolutely no impact on my diving.
halcyon, IMO, the only disadvantage of a STA is the cost. As far as the H line is concerned, it's another hundred bucks... but you do get the killer SS buckles!