I replaced the seat on mine with some industrial strength birch plywood and some heavy duty foam
Even though I way a ton, I ain't got a lot of arse for cushion.
It was fine before, but it is better now.
Both my brother and I toted ours all over the mountains of Montana. Every time we came back to camp, seems as though we would lighten the pack some, but we never left the seats behind.
When in open country, we had them tied to the back of our frame packs. In the timber with all the blow downs, we used them extensively as walking sticks.
I doubt they really weigh 4lbs..I would guess 3lb tops.
Thanks, bigjim