We work on all German cars, but at least 50% of the cars that come in the shop of W210 chassis cars right now. In all honesty, they seem require a LOT less "maintenance" than an old W124 chassis but I don't think they are near as robust. Give me a '95 well-maintained E320 with 250K on the clock and a '98 E320 with similar maintenance and miles and the W124 would probably be tighter, quieter, and the interior would probably be in better shape due to better materials. That being said, late W210's are great cars and easy to work on, and the problems other than the transmissions and spring perches are all usually minor. The M112 has lots of room under the hood to get to stuff, but I think the M113 V8 might be a slight touch more reliable and would be my choice.