from my research, it didn't make much sense to get 4matic in most applications due to the ESP on the MB's. probably the only thing that's a bit different vs. BMW or other sportier cars was the E class "sways" and leans more than the others. that said, it's also the most comfortable to drive and ride in for long distances/normal driving.
http://www.gkautos.com/00e320wagon.htm

good luck w/ your decision.

p.s. just bot my wife a 2000 Saab Gary Fisher Wagon. very comfortable ride also. this is my third car from him...very good resource.
http://www.gkautos.com/0095fisher.htm