I havn't used those but have seen them. I use a H.S. Strut seat with folding legs. It's very lieghtweight, easy to carry and saves me from all those "hidden" rocks and roots

Also the folded leg version doesn't sink down like the original fixed leg stool due to the braces on the legs. I don't go in the woods without it now, it was originally bought for turkey season but see's all the seasons now ;f