Whats causing steering to feel loose and goopy: E500

Hi,
The steering on my E500 (ex Starmark, 57K miles) feels goopy, almost loose and disconnected to the wheels. Needless to say, steering response has declined.
I began to notice this effect several weeks ago and it has become more prominent as of late. Shocks are new, springs are good. Control arm bushings are new. No vibration at 65-70mph. Have not looked under the car yet, but figured I would bounce it off some of the experts here to narrow possible lines of enquiry.
My instinct says it might be the steering damper. What do you guys think?
Thanks in advance
farrukh