Good point, Bluefish - the Atmos/Aura suspension does have some unique design features (particularly the lift loaders being integrated into the shoulder straps as "bars") that make getting the right fit a bit tricky. The first person who fitted me with an Atmos was clueless about it, and the fit was horrible. The second person knew how to balance the load lifters and hipbelt fit, and dialed it in perfectly. I still got a little bit of the old external "I pivot left; pack pivots right", but it was barely noticeable. The only reason I'm not still using it is that my Kestrel 48 is half a pound lighter, and I never carry more than 25 pounds.

However, I'll be cutting back at work next year, and look forward to taking more long-weekend trips - if extra food, clothing and water drive my weight up a few pounds, I could easily see myself switching back to an Atmos 50.