a friend of mine has the kuiu setup, he has the 1800 and the 6000 , not sure exactly what they are called, he is head to toe kuiu.
his system is a few years old and he has packed out a few animals, but he did say he loves it, BUT, it squeaks a lot, it is very noisy
we were sneaking in on some elk and i could even hear it.
not sure if this is common or not
i have been training with my kifaru setup since march with 40-60lbs regularly 4x's per week, and once a week with 80lbs
my pack has been soaking wet, i have used it for backpacking in and camping few times, no squeaks as of yet
I'm sure its a good system, but he was not happy how loud it has become over the past couple years
maybe something to consider, or a good question to ask other kuiu owners.
lots of good stuff out their, i would buy what appeals greatest to you and your wallet!