I don't think its totaly different at all, i have driven both , and to me its like apples to apples, whats different besides the motor? most were upgraded to super singles and anti lock brakes, that is it to me, the motor is smaller but delivers some more umph, but I found no noticable difference, not enough , i have driven some older 939s that were , are real runners, and some that were not, so it really is almost impossible to say they are different in my eyes. Its almost the same everything...