The Osprey Stratos 24 pack stands out for its innovative back panel. This panel makes the pack one of the most ventilated packs out there, but it also means the pack carries weight differently and does not fit as many things as efficiently as a pack like the Patagonia Refugio. The Stratos does have convenient features for hikers such as an ice axe carry and an easy to use trekking pole stash system. The Talon 22 and the Gregory Z30 have similarly designed back panels, but both of those packs leave less of a gap between the main compartment of the pack and your back, which means they are less ventilated, but hold weight slightly better. If you are looking for a pack that can hold a lot relative to its weight and bulk, try the frameless REI Trail 25 or Deuter Speed Lite 20.