When riding aggressively I find the 190/50 harder to turn in ... that is I have to fight it more to get the same lean angle. The 180/55 just falls into the corners better. Once in the curve and following my line the 180/55 just seems rock solid. And I have found this to be true through multiple brands. The 190/50 did fine for average to slightly aggressive riding but I still had problems getting the rear to stay put in a hard lean. This was true with Bridgestone, Dunlop and Pirelli.