First, I ve had Kleen Wheels on both of my vehicles for over 100k combined and still have the original rotors with no warping. I use OEM pads only, as that is what MB designed into your vehicle. If you want the stopping ability that is probably best for your car, use OEM pads and either clean your wheels more often or try the Kleen Wheels. Some of the other combinations of rotors and pad will change feel of your braking. Just my 2 cents for free.
98 E430(sport), 99 ML 320 (sold) , 05 C 230(sport) Mark