I had a 335d a couple of years ago, mapped by Simon at emaps, to approx 350bhp/520ftlbs, relentlessly fast, would hang off the bumpers of many a car. I have eibach suspension also to help looks and handling, but ultimately, just not the drivers car that I was after - it is a slush box after all, not dsg/SMG. I don't do a massive mileage a year - 15-18 k per year, so a petrol suffices mpg wise, and after a string of fast hatchbacks, the BMW felt just too grown up(I'm 36 with 3 kids!!!).
If I did more mileage and could afford a 2nd car, Porsche or so, then one would definately be on my list again.
It doesn't sound like a diesel, far from it, and I'm sure for you, coming from a diesel will tick all the boxes and more. Enjoy it, and especially enjoy embarrising some more exotic cars- e46 m3's were a favorite if mine. Oh and take it from me, ditch the sh*tty run flats, completely transforms the handling and ride.
Enjoy