I can't think of any "glaring" weakness that these cars have like some of the other models like W140 and W124's that have problems with head gasket leaks (on the 3.2 liter engine), wiring harness problems, or evaporator leaks.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".