I read the reviews and really appreciated the honest feedback, so now I reciprocate for those of you wanting an unbiased opinion. I purchased this pack to support my 4-day Grand Canyon trip which I just returned from.I was concerned about it not being large enough for my needs, but this is a great size for anything in the 1-5 day range even if you have to carry food, tent with you as well.I carried:-2 changes of clothes, 4 quarts of water, sleeping bag, food, walking poles, sandles, swim suit, toiletries, first aid, thermarest, sleeping bag, hammock, GPS, flashlight, matches, batteries, camera, snacks, poncho, moleskin and more.The pack is highly adjustable and I found it very comfortable to carry despite being fully loaded. It has lots of ways to attach other gear to the outside of the pack securely and really suprised me with it's high-quality zippers (my pet pieve), thoughful design and great value.If you tend to overpack, you may want to go bigger, but I love the size and appreciate being obligated to evaluate how important items are to lighten the load. The rain-fly is a great bonus since it is removable and the top-removable fanny pack makes short range hikes more enjoyable. Love the integrated bladder pouch and even the waist belt is comfortable to wear.Don't hesitate on this one....you won't beat the deal.