The Arc'teryx Altra won Backpacker Magazine's Editor's Choice award in 2010.
Gear Institute gave it an 82 out of 100. High, but they rated other packs better.
Outdoorgearlab.com rated the Altra as their #1 pick out of 11 packs reviewed.
I have no experience with this pack. I'd like to own one, though. Looks like it would be very comfy. It's adjustable to a high degree; the shoulder straps attach via a peg board (pic related) and you can move the straps around the board for the perfect fit. The waist belt is on a rotating pivot, which looks awesome.
