Yes I agree, I tried Corbin, Russ Meyer, and ended up with an ultimate. The Ultimate was the best for me, but the stock one was not too far behind that.
On the full wing the seat that came with it was simply miserable after a short while. With the full wing being even more cramped that the F6B it made it harder to get comfortable. In comparison getting the Ultimate seat on the F6B was a major chore but I did get it on. Seemed like the holes didn't want to line up without some major persuasion. With the full wing the seat went on with no problems at all.