I've had this pack for a little over a year - replacing a 9-year-old Arc'teryx Naos 70 Pack. The Naos was always too small in capacity for me - having always to strap gear to the outside - but it was extremely comfortable and bombproof. I hike an average of 600+ miles per year, never with less than 55lbs. The Xenith has been amazing in terms of capacity and gear access - but it is flimsy, uncomfortable, and the sternum straps are useless. Understand the frame needs to be lightweight, but it is SO lightweight the pack splays out like a water balloon when it's full of gear and set down on the ground. The lack of rigidity, combined with not much protection in the back area, results in anything hard in your pack poking directly into your back which is VERY frustrating on long hikes with a heavy pack. The sternum straps are TERRIBLE (I've never had a problem with buckles, like other users have mentioned). They freely slide up and down their channels and NEVER stay where you want them to stay. Under load, they'll quickly find their way all the way to the top and I find myself constantly having to push them down. During a 10-day Denali trip, one of the sternum straps was ripped off and lost when loading/unloading from the sea-plane - which resulted in 10-days of misery with an adhoc sternum strap in place. The Arc'teryx system of a "locked-in position" sternum strap is far superior, functional, and comfortable. I will keep this pack because I need something in the 105L range and very few others make a pack this size. However, if Arc'teryx comes out with a 100L+ pack, I'll dump this Osprey Xenith in a heartbeat and pay triple for an Arc'teryx.