One of my brothers used one a bit in Nam 1967-68 I crawled into it a few times.
I had plans to work in Olympic National Park backcountry in 2004 where quite a bit of physical trail work is required. Rather than take a tent that requires some site selection decided to go with a Hennessy. I did not anticipate the fantastic comfort or the theraputic effect on my back.
"There's no accounting for other people's taste in love, fiction and huntin' dogs." ---Mark Twain