I have a strange feeling about the steering on my 560SEL. I don't think that there is too much play, but it still wanders more than I would like. The mechanic I go to did some much needed work to undo the sins of previous mechanics, but it still feels funny. I am planning on taking out a 126 he has for sale to see if it handles like mine. When I drive at highway speeds, I can't relax much as the car tends to wander and needs steering corrections often. There is little play; when I move the steering wheel, the tires react immediately.
To date, I have put on 4 new tires, new steering box, tie rods, steering shock, various bushings, front shocks and a good alignment.
I am thinking that the rear suspension links may need to be changed although the mechanic doesn't think so. I just know that something isn't right. My 300E is much easier to drive.