Most Mercedes engine have had some form of variable valve timing for a long time. I've test-driven the new diesel E320 (wanted one to replace our 98 E300 turbo) and it's an amazing car. Unlike my C230, there is no way to "feel" the effect of the variable timing. The C230's four banger has a "step" at about 4000rpm.
I suspect that the variable timing feature is different from the gas non-turbo engines in that it probably maximizes off-turbo low rpm performance. The CDI is very quick with incredible pull right from idle. Our OM606 engine'd E300 turbo made tons of torque and had no off-turbo stumble, but the CDI engine is stronger across a wider range. In the W211 E-Class line, it's easily the choice, but at almost $90,000, it's just too expensive. Our 98 had a base of $59,995 and even optioned out it was a sub $70K car.
