There used to be a big debate between 2 legs or 4 legs that I thought was overblown. It was a great sales technique at REI to say, "this chair has 4 legs! That chair you need to use your two feet as two of the legs which some people don't like at the end of a long day." It was a persuasive argument but I found it specious. Whether your chair has two legs or four, both your feet will be resting on the ground. The two legs of the two-legged chair took most of the weight. I actually liked that the two-legged chair allowed you to rock a bit.

I think the Helinox Zero (4 legs) settled most of the debate because it is lighter than the Alight Butterfly (2 legs). I like to be able to rock but I don't like paying a weight penalty for it. Combine that with the better sales pitch of the four-legged chair, means most people who cary a chair seem to have settled on the Helinox Zero.