I agree totally with your regarding the Germans designing the car engines more toward economy, however now at 18000 miles my 2.0Jtdm (160 bhp) is still being outrun by my wife in a 7 year old (120000 miler) 130bhp Passat TDi estate. Although I was peddle against the stop, she wasn't and it was 60+ before I stopped losing distance to the Passat.
So if the 159 was tuned for performance and not economy, this would not have happened. So clearly it is tuned for neither. Further my wifes other car 320d (2 years old and 30k), just leaves the 159 for dead and gets 48mpg!
My point is Alfa, wake up and develop the engine and get it to work properly and perform, and be as enjoyable and fun to use as the rest of the car.
Ask yourself one question would the 159 ti 2.0Jtdm be a better car if it had the 320d engine fitted? My view it would, and no one would buy any other car.