Does OP have other T4R owners near him that will let him drive their trucks and vice versa? I think experienced owner will be able to tell if something is not right fairly quickly. If there is no fading and no unexpected changes in brake pedal feel, it could be hardware is OK and OP's expectation for brake pedal feel is different from his German car experience. My '05 C55 brake pedal is firm and does not have nearly the travel as my T4R. I am not alarmed at my T4R's relative softness because the brakes have stopping power, are easy to modulate, and do not fade. There are no unexpected changes in brake pedal feel. I don't want to diminish the importance of getting the hardware right but I wonder if personal preference is in play.