Never had a problem with mine. No real change from cold as they never really warm up when in traffic.
However, with a bit of enthusiastic driving through the twisties they do improve and become even more responsive. It's like the car is enjoying a good hoon as much as me
I run'em on mine and no problems, you'll stop OK in traffic etc but they do work better once warmed up and they will wear your discs more than std pads ( what fast road pad won't?)