I purchased the EXO 3500 after giving up on getting a good fit from a different manufacturers “high-end” pack. I tried two different packs before purchasing the Exo, and both gave me significant upper glute and back pain when the load got higher than 60lbs. The Exo fit like a glove straight out of the box, and with some minor tweaking on the fit, I was able to wear this pack loaded out every day for a week long elk hunt in Montana with ZERO issues! I did not have any hotspots or back/hip pain at all! Further, I was shocked at how much food and gear i could fit in the 3500. I had 6.5 days of gear and food including a tent, sleeping bag and bivy gear. I love the pack and have recommended it to several friends. Thanks for building a quality product at a very fair price!