I had my stock deluxe seat modified by mean city cycles and was thrilled with result. In my quest for a back rest I tried the grasshopper which was a complete joke. To this day I still have no idea how anyone could even ride with that thing installed. I also tried a mustang wide tripper solo with back rest, which was way to far forward for my liking. I just scored a Corbin solo from a fellow forum member, and it seems vastly better than all of the other aftermarket options I have tried. Can't speak on the comfort of the backrest, because I have not picked one up yet, but the seat by itself is fantastic so I'm confident the back rest will only add to the comfort.

 

Mustang Sport Solo (different from the vintage solo) with back rest. Same seat fit both my CrossBones and Fatboy