why would you want to carry a bunch of extra weight on your person? (not counting the firearm)?
I would never carry tools or hard things on me. Especially right on my back. Seems like it could get painful or dangerous if you land on it. The adventure vest is good if you want to carry small stuff and the hydration pouch portion of it in a vest format wears nicer than a hydro backpack. It's not for everyone for sure but the wearability of it versus a backpack to me is better. With conditions.
I have tried to use my adventure vest a couple times and depending on what you have on under it, results can range from OK to suck. It usually sucks if wearing over thick or hard armor / chest protector so I don't bother with it. It's okay over a jacket or something.
Honestly the best way to use it would be for the hydro bladder and maybe one or two small pouches. You could also do the same thing with one of those new style fishing vests for like $30 from Bass Pro.
It was an experiment. I would not be too keen to pay the $189 Klim is charging for their take on it. I still like mine but it's not always the thing to use.