The main difference between older and simpler MB diesels and the newer ones comes down to cost of ownership, with the older ones you can drive them until rust kills the car, with the new MB's 100K or the end of extended warranty is when you need to move on, if you continue driving, it will cost you an arm & a leg, and if you can indeed afford an arm & a leg you might as well buy a new one and be happy.
A new MB from quality standpoint is no better or no worse than any other car, it is just expensive thanks to its reputation derived from its glorious past.

Vahe
240D 77