Anyone who has driven a 'new' high performance turbo diesel will know what I am torquing about. The 'new' Alfa JTD, 150 bhp = more torque than the 156 3.2 V6 GTA. In the real world of driving, ie, mid range punch (forget the traffic lights), these TD cars are stormers! Drive a 5 cylinder JTD and it WILL make your 2.0 petrols feel tardy in comparison. Almost all major manufacturers are now making flagship high performance diesels. New Bentley, Peugeot have their ACE/SPADES concept coupe and Lotus are making a tiny engined diesel with mighty performance and economy (making as a prototype/showcase that is). If the 147 had come with a 130 bhp TD, I would have had it without a doubt.
The 224 of the 156 quoted is for the current 140 bhp, the new one at 150 bhp will have nearer 250. Consider the current 911 Carrera has 'only' 273!
Downsides, a bit clattery on start up, but once warmed up and on the move, you don't notice and usually slightly more expensive to buy new.
Also insurance is several groups lower and a higher second value.
Try one, buy one.