I get almost as good mileage from my 240D as I did my Mitsubishi.
However I'll gladly change the water pump in any MB, as to have to put a water pump on that Mitsubishi! It was an all day job that required pulling the timing belt, alternator, and disconnecting one of the engine mounts!
The fuel pump was another great one... had to put two in her in less than 140K. To get those on.... you have to pull the intake manifold and complete injection system! Another 10 hr day!
I love my Benz, and soon all the cars in my drive will be MB!
76 240D (W115) - 555K miles
78 300D (W123) - 200K+ miles -- SOLD