All Around Best Pack
This is without a doubt my favorite pack of all time. I have the older orange version, and it serves me well for climbing approaches, as it can swallow a full trad rack easily. The outer mesh pockets can expand and then contract, I have not stretched them out. The side pockets accommodate a nalgene silo 1.5L bottle without complaint. The pocket in the front can easily hold your shell for those times when you take a break on the trail. The pack is very light, yet still retains enough organizational options to be functional to live out of. The pack will carry 30-50 pounds of gear without too much trouble.
I find that the straps are also incredibly comfortable. Osprey has made a way for the straps to all be tucked away so they are not dangling around. The hip-belt pockets are also mesh, so you can put something in there without it uncomfortably rubbing against your hips. The pack rests mostly right up against my back with little breathing room, however it is not overly hot and uncomfortable. The straps are easy to adjust, even with cold hands.
I traveled through India for two months using just what I could fit into this backpack. It is small enough to take as a carry-on, yet large enough to have room for multi-day summer backpacking trips. I would only recommend this as a multi-day pack if you are a light packer however.