I owned a 1989 SL560 for five years, sold it 16 months ago.
Great car, not Secretariat but not Porky the Pig either. I think I wrote years ago that while the 560 is a boat it is more like a Frigate than an aircraft carrier.
I will say that the previous owner, Choc, did all the right maintenance so I did nothing other than routine stuff for all the years I drove it. I really enjoyed the car for what it is.
One of my neighbors used to tell me that he would see my son driving me around (Driving Miss Seahawk) with the top down on the weekends and wonder how much fun we were having.
Lots. Drive westbound to the sea....
Concerning the 380, if the price is comfortable and you do your homework, expect average performance but maximum smiles. Only pay enough for it that you can walk away should the mechanicals/electrical go South.
This link will look familiar:
http://www.peachparts.com/shopforum/