With only 500km on the '09 and having come from a stock '08, I have noticed a few differences. These are not in any order nor do my comparisons come from years of riding Harleys. Since it isn't broken in, I obviously haven't put it to the spirited riding test yet. 1) less vibration at idle and at speed 2) lower sitting position and more comfortable seat 3) Less heat. Not a radical difference but noticeable. 4) Less wallowy in a corner, especially a corner with a dip or bump in it. Certainly not sport bikeish nor expected to be but much less disconcerting. 4) XM antenna still sucks. Gotta move it. 5) Still get helmet buffeting over 90-100km. Didn't expect it to go away but damn, it's annoying. Yes, I've tried 4 windshields and adjusted everything. 5) Drop dead gorgeous colour, octane orange/autumn haze.