I have no issue with this. I've done a lot of miles in both a new M3 and the new M5, and to be honest i find their engines lacking. Lacking torque, mainly, which i think is very important in a sports car.
The thing is, i've also done a fair few miles in a 335i Coupe, and i swear that if you gave it to your average petrolhead, and didn't tell them what it was, they would swear it was naturally aspirated.
The 335i and 335d engines are absolute masterpeices of engineering, and prove exactly what BMW can do when they try.
I don't own a BMW, just to clarify, i'm just a fan of their engines. Plus the X6 xDrive35d is a frankly astoundingly good car. If you don't believe the hype - just go and drive one.