I didn't mean for this to turn into a discussion of relative engine merits.
I did start out, as I said, looking at the V6. In fact the first car I test drove was one. In terms of cost, as a third car, it needs to be able to perform in all three of the 'potter, pose and proper run' categories with the occasional commute too (when I lose the 147 to my 18yo). It was the £500 road tax that put me off the V6 to start with, real world mpg does not help. The Jaguar was doing 16mpg overall, the way I drove it!
I have only had good experiences with diesel engines in my past. With a growing family my 156 had to go for a Freelander, 'you don't want a petrol, sir' BMW TD4, thank you very much. I owned a petrol 406 coupe, lovely looker, worst engine I ever owned, gutless piece of... When owning 307SW (small seven seater) 2.0 HDi much, much better engine. Best diesel (to date) 2.2 PSA unit in Ford S-Max. Now that could shame many a petrol driven motor.
Anyway, that is my preference for diesel, but really looks, space (occasional 2+2 use) is what brought me back to Alfa. Other contenders? Don't laugh, thought about most VAG 3.2 V6 from A3 to EOS, TT? Err no!
Finally, would I buy a 2.2 or 3.2, if the right one came along? Absolutely!