not sure I'm fully qualified to give advice, so I can only tell you about my own personal experience. I wanted a new car that looked nice, had a decent amount of power but wasn't too heavy on mpgs. I decided I loved the Brera, so went to have a look at a 2.4 diesel and found it was the best of both worlds. It's got loads of pull and great mpgs if I take it easy. I paid 10,500 from a garage and it's got 26,000 on the clock...I absolutely LOVE the car....by far the best car I've ever had (had plenty of beemers and mercs in the past).
I reckon the 2.4 diesel is a great engine, mpgs if you take it easy, or lots of torque if you're in the mood. Only had it a week, so not getting great MPGs at the moment, sure I'll start taking it a bit easier soon though :-)
good luck with your search