I used an Aarn a few years ago on a Grand Canyon hike (brief comments in that link later on) and I sort of bought into the hype. Sort of. At the very least it was very nice to balance the load when you’re carrying absolute tons of water weight. But, yes, I thought they were overbuilt, and definitely not light.
@Dave- I looked into the studies that were being proposed as proof that bear spray works better than firearms a few years ago, and found them all to be either obviously biased or misrepresented. The one everyone tries to quote, for instance, compared 17 (?) instances where bear spray was deployed to a couple of hundred instances where firearms mostly were present but not used. That’s hardly a fair comparison. So I think we still can’t say that we know what works, though admittedly I haven’t done a literature search since then. No doubt, though, that spray is lighter and comes with fewer legal entanglements, as well as having the benefit of not being fatal. I’m all for bears, wolves, and whatever else being reintroduced wherever possible.
My prior TL;DR discussion is here.