I thru-hiked the PCT with this pack in 2011, and I was super happy with its performance. I used a size small, and was able to adjust the waist to accommodate losing mass along the way. Big enough to fit the gear I needed over the 5 months, plus when I needed to cram a bear canister, ice axe, and crampons in there, it stretched to fit it all. I was also able to pull off the lid and use the rest of the pack partially filled as a day pack for slackpacking. It handled a lot of wear and tear, and stayed together even sliding over ice and snow. It survived the trail much better than the pack that I used on the AT. The side pockets are a little difficult to access, though after 1500 miles I figured it out, and the lower back has an odd shape that took a little getting used to from my Osprey. Overall, it is a really great pack, and with a good washing, I plan on using this for future trips.