Agreed , normal brakes are indeed enough , but same goes (IMHO) for a normal Carrera S compared to a Turbo.
In fact , I would argue that the steel brakes are extremely good. But PCCB is better , nicer , lighter , stronger, and more. That is why I chose PCCB after testing as I chose a Turbo over a Carrera S. I went for the best (for me at least)