I’ve tried out sg sky 5900, kifaru duplex lite, big kuiu , exo k4, initial ascent, Mr metcalf,and akek this year looking to upgrade to a high end pack. At least a couple miles in each….For me the stone, kifaru, and exo are a couple steps above any of the others (initial ascent was very nice too, much better then the kuiu, Mr, or akek)
My opinion, the exo was a step above the stone and kifaru in basically every way. They were all great packs though. The stone felt amazing under load, but I don’t love the bag design for organization. It was between the sg and exo in the end. The k4 was just a little better across the board. One note, the sg was initially more comfortable for me, but once the k4 lumbar pad broke in…. I have no doubts the k4 is the top hunting pack on the market right now for me. Haven’t tried the ark frame, which I’d love to…. But I’m extremely happy with the k4.