My Aeroad with di2 and 60mm DT Swiss carbon hoops at 17.9-lbs = 12-14s slower up a 1.9 mile local climb than my S-Works Roubaix weight weenie build at 15-lbs. Not a huge margin, but I definitely prefer the feel of the Roubaix for hilly stuff. I'm no pro, so the marginal performance gains from aero is purely for entertainment.