I'd agree that you have to test them before you get critical, but I've done enough testing to know that for me, hammocks don't work. I don't have bad knees unless I try to sleep in one, the curve of the thing puts pressure on my knees in ways that I can't stand, the more I try the worse it gets. If I was swamp camping of course I might try it, and if you're hanging off a rock face and camping there's no other choice. But I sleep better on the ground. To me the ground is bothersome for a couple of nights and then I get over that and by the time I've been doing it for a week I'm fine. I haven't reached that threshold with the hammock concept.

Actually I'd probably skip the hammock even in the swamp, since I've been able to sleep well enough in a canoe overnighting on a lake, tied up to a tree. I have a sailing rig with pontoons, so I just put the pontoons out to maximum and set a lawn recliner over the seats, sleep on that. Knowing there's a solution that doesn't involve a hammock I'll probably skip the hammock if I ever go swamp camping. (Would like to try that, looks like fun. Things always look like fun.)

I'm not seeing that the camping hammock is working out all that great longterm. Too much tree damage in campsites that are used a lot, and trying to put one up often involves clearing new spaces, so you have to ask if that's really camping without leaving a trace. One person uses the tie-up trees, ok. Two people, probably that makes some damage. Not everyone will use the strap rigs that aren't supposed to leave marks. Even that isn't going to work out on trees with bark that won't hold up to this, and how many people know which trees are tender and which ones aren't and what time of the year they're vulnerable? Tie up to a hickory in midsummer and it's like an iron stob, but in the springtime when the sap is running you'll probably blister the trunk. How many permanent camps do we need out there, anyway? If hammock camping is creating new camping zones we should just chuck the idea.