stockers for the first few months I owned the car, and switching to the 18" ADRs (aside from increased stiffness in roadfeel) as far as those aspect are concerned. But you are absolutely right, the differences are there no matter how intangible they may be. At extremes like autoX and drag racing the differences would be more easily reflected in times and, you would have to be a fool or simply not care about results to go with heavier wheels.