G Posik,
My buddy has one and used it for 12 nights on Kodiak last year. I was a bit jealous, but you are right they are hefty for a backpack hunt and they are spendy as well. It depends on the hunt whether or not they are worth it. Being as he was 20+ years older than me I am sure it was worth it for him and in 20 years it'll likely be worth it for me. Cool little cots for minimal weight penalty.
This guy made his own lightweight cot. Don't know anything about it, but it looked pretty cool. http://www.instructables.com/id/Ultralite-cot-for-under-30/
I am looking for some heavier rods as well with my 215lbs vs. his 130lbs might need a little more support. I will let you know what I come up with on the rods. Might have to start a new thread once I get things started,It looked like a pretty good concept. I'm going to try aluminum as well just because he said he is only like 130lbs or something like that. Probably will try some thicker carbon rods too.