We bought a Corbin for our '02 ST1100 when it was less than a year old. We love it with the step up for the passenger, making it comfortable for both of us. They custom made it so that it is not as tall for us under 6 ft people.
The one thing that we learned, is don't have them make it too short, as you will have less cushion.
Honda says the padding is soft on the outside and harder the deeper it goes. Where as Corbin claims theirs is the opposite and you will need to ride for 20-30 minutes to have it form to you. I have found that it is on the uncomfortable side until it forms to my butt after 20-30 minutes.
The Corbin replaces the original Honda seat, so you can always go back easily if so desired. Not like some other brands that use the original seat frame.