I too am a big fan of camp chairs. I have a Monarch Butterfly. Many people get weirded out by just having two legs, but it was a non-issue for me when I am sitting in it. It is very comfortable. Your feet really only provide stability and don't take load. The only time I notice having just the two legs is when I sit down. The chair topples over so it is a bit awkward holding the chair and trying to get your butt into it.

I did receive the Helinox zero chair recently as a gift, but I haven't verified any weights. It seems like a nice chair and does have four legs. The fabric isn't as heavy duty as on the butterfly but it seems fine (and I weigh more than the rated limit).