I used this pack size large on a 21 day trek in Nepal around Makalu I packed my down bag, Thermarest, sometimes the tent, snack food, chaco's,extra set of clothes, hygiene stuff,first aid, 100 oz. pladder, MSR filter, and other gear headlamp,knife, etc. If you are a serious about going light then this is the pack use compression sacks for everything u can and it will hold all you need. Even used it as my carry on the whole trip. As far as comfort on long hauls it is great. Began the 21 days with a 37lb. load sometimes 40lbs. when carried tent by the end had 35lbs. and was awesome no matter the load. I will add that even though you need a rain cover I got dumped on for about 2 hours before I stopped to dig my cover out (keep it handy) and only a few things got damp. Hip pockets are real handy, should have kept my cover in one. Only down side is loading and unloading. I would add a bottom load zip as well then I would call it near perfect. Use it all the time on short hikes in CO perfect. Osprey makes some tough packs this is my Favorite.