I just installed a Corbin Hollywood solo seat and backrest. The Corbin seat is a firm leather seat but comfortable, not squishy like the OEM seat. The backrest transformed the comfort to a level that has to be experienced! I am 5'-11" and 220. The seat raised me about an inch above the stock seat height. I have not sat on a Mustang seat in order to give an objective comparison. I am very happy with the Corbin.
I've had a chance to put a few miles on my Mustang, and I'm pretty much sold on 'em. The studded one even looks pretty good on the Vegas. I wasn't too sure, but I got such a good deal, I couldn't pass it up, turns out it looks pretty good.