I was following a diesel the other day and was mightily impressed by its overtaking prowess:
Yuk what was that!! Nailing it past a tractor with a maybe 50k box doing at best 30.
Not that I have much to add, just that I came from a 4cyl D4 V40 with P* running around 210bhp.
Loved that car and that engine, so smooth, yes it had the diesel dirge, with the volume turned up all I felt was the torque surge and enjoyed the lazy cruising a Diesel gives, such a relaxing daily commute with the beans for normal overtaking.
I disagree with Meerkat though 300hp is not to much through a well set-up 2wd chassis on tarmac... but I digress.
I now have a petrol ST and have seen my fuel consumption nearly double from 45 to 25, still early days so hope to see improvement.
What I do enjoy though is revving it out and enjoying how a petrol feels, not so much how the tank empties...
Dont get hung up on MPG though, test drive both see what you will be happy with both engines are great and as a long term ownership Id say both would be fairly equal in the end.