I just rebuilt the rear suspension on my '86 300E and with the Bilstien comfort shock the ride is very tight and firm. The car really hold on a tight corner.
I was of the impression there were only two grades of shocks, comfort and HD. Also, I was told not to mix shocks with the springs, use HD with HD springs. Depends which spring you have on the vehicle.
Check out the link with the advice from the group... 300E - Front End movement