Me, too. Although I’ve used the Thermarest trekker chair kits over the years, for the last three years or so, I’ve simplified to a Z-seat (closed cell sit pad) and my pack, a la Colin Fletcher: the Exos and Atmos packs I’ve used have a perimeter frame, and allow me to use a hiking pole to prop them up as a backrest. (When I started 40 years ago, I did the same thing with my external-frame packs; come to think of it, the Atmos and Exos are really high-tech external frames.)

Trees, rocks, and logs also work as a backrest.