I have used Kifaru, seek outside, stone glacier, and Mystery Ranch. They are all great and would have no problem using any of them. Though mystery ranch packs are needlessly heavy and the last I would choose.
The waterproof fabric the seekoutside packs are made out of it pretty darn nice for extremely wet environments or packrafting.
The Kifaru EMR 2 is my preferred setup as it can be a day pack or haul super huge awkward loads though is a tad on the heavy side.
I feel Stone glacier has best balances the feature to weight ratio and could see me using one again.
Hope that helps.
