The comfort shocks might just be it.
Most people either use standard, heavy duty or sport shocks. comfort is usually too soft for most people.
If you hate a firm ride, sport is not for you, and HD might be too firm as well. standard OEM would be well of course factory ride.
If its bushings, or maybe sagging springs or something, then look into the sportline upgrade.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.