Limb, I bought one in the fall, because they had a good deal going at that time, also. A guy from Des Moines came out and demonstrated it for me. (His cousin is the guy who invented it). He is a big boy - well over 6 foot, and approaching 300 pounds. He had the larger size, and it worked great for him.
I didn't get mine til partway through the bow season, so decided to wait til spring to get used to using it. I'm looking forward to using this 'stand' in the fall. I plan to have steps installed in several trees ahead of time, which will make it easy to move around and hunt the wind. They really do break up a hunter's profile, and they let you shoot in every direction.
I bought some strap-on steps in case I want to hunt a new place, or move to a place that isn't already set up. I was told that some guys put three of them on one strap, and use that one for the top step, which allows them to step on any side of the tree. They use the climbing sticks a lot, also. I plan to start testing mine out in a week or two. I want to be confident when I use it. Let me know how yours works out.
Muddy, my limited experience with one of these indicates that they will be very comfortable. When I tried it out, I felt like it had very good back support. The guy who sold it to me, said he has sat in them for up to 8 hours. I doubt that I can sit anywhere for that long - no matter how comfortable they are.
