RE: what is that thing called?
I use 4 LW sticks to climb the tree and either tree steps or 5 strap on steps rigged to a single ratchet strap for the "platform". Another Tree Saddle guy I know just uses tree steps for getting up the tree. I've heard of a few that use climbing spikes but not many.
Shooting out of the saddle came easy to me but it took much longer to be able to maneuver around the tree. Once you get the hang of it, it's a valuable weapon in the bowhunters arsenal.