Thoughtfully laid out and designed, the Camelbak Trizip is one of my all-time favorite packs. It sports what is arguably the best shoulder harness on the market, the Futura Harness from Mystery Ranch, and basic padded belt. It also borrows MR's famous Tri-Zip layout, allowing the user to access the bag as a top loader or to the contents in the bottom of the bag. Camelbak has added a great admin pouch and an enclosed and insulated bottle pouch to each side. There is a top pocket, a zippered bladder pocket (which will fit a 13" MBP!), an internal sleeve pocket and a few other goodies. The pack comes in around 2100 CUI or 34l in volume, so it is a medium to large bag for EDC, or pretty perfect for fitting in overhead bins while flying. There are licensing issues to blame for this packs discontinued status, but if you can find one, it is a worthy pack to add you your collection.
Happy carrying, all!