Soft organic pads are the answer. They give greater braking with less pedal pressure and decrease the wear on the rotors.
MB doesn't use and specifically warns against using metallic pads. They will definitely squeek, groan, grind or crouch depending on vibration frequency. Varying significantly with temperature.
Most manufacturers of pads make a variety of compositions includin MB. It seems that different driving styles affects the overall proper composition. We have had greta luck with Repco Delux. Also OE suppliers Textar and Jurid have good organic.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician