Took the stratos 36 to Peru for a 5 day hike through the Andes then to Tanzania to climb Kilimanjaro. I'm 6" tall with a fairly normal torso length, and the medium fits me perfectly. Osprey nailed it with this pack. Very durable, very comfortable. Built in rain cover is perfect, and well placed. Also like the walking pole positioning on the shoulder strap, makes it very easy to put poles away when they're not needed. The ONLY drawback I've found with this pack after plenty of travel around the world in the last six months, is that it doesn't sit upright due to the 'airspeed' back. The back is curved to allow for air to flow off your back, which is very helpful in the heat - the trouble is, when you put the pack on the ground it will fall forward because of the design, so if you need to get something out of you have to prop it up while digging around. Still, this pack is amazing, and EASILY worth five stars - great value, great pack.