Wore mine for a few miles today, took my 2 year old for a hike, my normal hunting day trip load out is a Tarahumara, but I threw that in the umilindi and added some water bottles knowing I would need the waistbelt and a sturdier platfrom once my little guy went out and I would be carrying his pack/ him back to the truck.
15-20 lbs, that thing is comfy for all day. Even with poorly planned, uneven loads.
