Ok I have a Corbin I bought off ebay for $125. you can usually find them for the busa in the $150 price range. Overall I'm happy with the corbin, and can't remember the last time I suffered from sore butt cheeks --wait yes I can i rode 1400 miles from NC to Daytona and back.. I bought the corbin the day I got back and haven't suffered since. The seat is wider and higher than stock and also has a slight upturn at the tank. Its pretty much a SADDLE. It keeps you planted, comfortable, and secure which is great on long rides, but takes some getting use to in the twisties because you can't just slide off the edge of the seat in the turns.
I'm looking at trying a gel seat.
If anyone has a gel seat and wants to try out a Corbin, I'ld be willing to swap seats for a couple of weeks.