Really just a money thing to me. With the way my bike eats rear tires it eats all my mod money. I had one on my old S4R and really liked it.
Like Capo says once you adapt to the slipper it's even better. You get good engine braking, but never enough to slide the rear wheel and things are smoother at speed in the tight turns.
Like I've said before, the only time I have found a problem is if bump starting is required - that will just not work.
LA
