Personally, I've never used a Kuiu pack. However, I have a number of friends (6) that use them. All are accomplished hunters and all have carried weight over 75lbs without issue. One has carried well over 100lbs of meat on multiple elk hunts with whatever Kuiu frame he owns (I don't know the names/models of these packs). None are broken, none of these guys complain about noise and none of them have any intention of changing packs simply because the packs they use work for them.
There are better packs in my opinion, but I'm not going to try to convince them that they should change because I like a different pack.