I've been in a mapped E92 330d with 295bhp and also in a standard E92 330d 231bhp. Both very quick cars, effortless power but not as urgent or exhilarating to drive than a petrol turbo imo. My ST has approx 280bhp and 340ft.lbs of torque and feels a lot more exciting but on the road there probably would not be much in it. Horses for courses however.