Hi Leif, I completly understand everything you're saying. I'm debating getting the Dual Tour seat but I found on Corbin's website that it has a seat height of aproximately 27", while the Roadster's stock seat height is 29.5". That's a big difference.
If the seat is lower, and you sit further down in it, then your knees would be bent at a tighter angle, and may be uncomfortable. Also, the positon of the handlebars would be off since your but would be sitting lower in the seat, the bars might be too high. Because of these concerns I'm optiing to not get the Corbin and maybe get the Triumph Classic seat that allows for the rider back rest. I just want to do something to eliviate the need to hold myslef upright with my arms when the wind is blasting me in the chest at 80 miles per hour for hours at a time. That's what I'm looking to fix. I'm 6 feet tall by the way.
Hope this helps you and anyone else. Ride safe my friends!