Well, I'm running the M.Plus on a folding commuter bike with 20" wheels, so maybe that's the difference. I didn't notice much of a change going from the M. Supremes. Also, I'm not a "high-performance" rider, so I'm probably not as sensitive to small changes. What I *do* notice and value is the freedom from flats. Nothing is much worse than a flat when I'm supposed to give a lecture or see a patient... it sounds like a lame excuse to anybody but a bike commuter!
Steve