I like driving the diesels but find them difficult to justify from an economic perspective in the U.S. The price difference between diesel and petrol eats up at least half of the fuel savings, depending upon where you live.

As well, each diesel has some problem areas. The Bluetec OM642 suffers from leaky oil coolers and failing throttle flap motors. The former is running $2500 to repair and the later perhaps $1500. The CDi OM648 has the throttle motor problem, and it's usually caused by sticky throttle flaps in the intake manifold. It's more DIY friendly, but still a fair amount of $$$.

I would point you towards a nice E350 gasser. Less expensive to buy, less prone to expensive engine repair, and marginally more expensive to run. I think it's the winner now. I say this as the owner of an '08 Bluetec.