There is an interesting thread titled "What's Wrong with Mercedes-Benz?" in the Edmonds' Townhall.
Read it at
http://townhall-talk2.edmunds.com/WebX?14@171.gaPpaxxT1tN^3@.ef08228/0
I liked what one guys had to say. He was a long tiem MB owner (three of them including an SL) but was fed up with the "problems" (MBUSA won't call them problems) in his E-calss (head gaskets, radiator, etc.) and now he is a happy converted Lexus owner.