I have the stocker and a Sargent that came with the bike. I really didnt feel the need to replace the stocker, as it only started to get tiresome after 200+ miles or so, and even then it was minimal.
Then again, I'm a diehard supermoto guy, so my rear is overly tolerant of bad seats, haha.
I did put the sargent on this weekend just for kicks, and it's really pretty darn nice. It does sit you up a little bit more though. It wouldnt be much of an issue if you arent really tall. I'm 6'1 though, and it kinda pushed me up a little bit more. Maybe some more seat time will help it settle in a bit more.