Thanks for your thoughts on the Corbin. I have a Corbin on my 78 GL and it is hard as a brick and I like that it is a firm seat. I tried an Ultimate on my Valkyrie and my F6B and hated it, they are way too soft for me. The Mustang is a firm seat that I like but no backrest.
I have no problem with touching the ground, I just like the lower position.