Rather than search for old thread, just an update. Finally decided on the Continental PureContact LS (LS version is new). Bought four and got a $70 credit card. Also a free three year protection plan/Roadside Assistance from Continental. They are the top rated in comfort and quiet, which is most important to me.

 

 

 

Only got about 25 miles so far, but are more comfortable than the Michelins that came with the car. Seem quieter as well, but really need to drive on I-85 in Northeast Georgia. Between the lack of insulation and the Michelin tires, could not even carry on a conversation on most of it.
As I noted, these are the new LS versions, which Continental says are 50% quieter than the previous PureContacts. Incidentally, they were $200 less than Michelins before the credit card.

 

Exactly the same with the factory bridgestones. Now I can carry a conversation, but there is still the steady howl of tire roar >50mph. I think I might just be expecting too much of any tire on this w212. I came from a range rover sport that had acoustic glass and weighed nearly 3 tons, that thing was whisper quiet with the Michelin all seasons I put on.