I just came off a Suzuki Boulevard 109 with a Mustang seat. My wife says her bottom is comfy but when I use the driver backrest, the adjustment knob kinda pokes at her so I have to either screw it in all the way or remove the backrest. Had more room front to back on the jap bike. We both enjoy the extra set of speakers & storage you get with the trunk, however, & it sure is nice having the extra tail/brake lite as well. Might want to test one out at the dealer before you spend the big bucks. I don't know if the passenger backrest affords more room than the trunk. If it wasn't so expensive, I wouldn't mind having both.