The turbos have been in use far longer over there than in North America, esp. the 2.1L engine. It's a calculated risk when purchasing this engine. The decision is based on the available information, which is good but limited, and historical MB diesel longevity, which has been well above-average.

The powertrain, exclusive of the engine, is excellent. It's a 7 speed with 4Matic. It's been as reliable as Quattro, but not as reliable as the Subaru AWD (the two heavyweights of AWD tech). I love Subaru cars as well for reliability and COO. If they just made a mid-size diesel that looked half way decent, I'd have seriously considered it. They are mostly ugly cars that last a LONG time. A blessing with a curse.