I have just over 3000 miles on it. That mileage is city only - but even taking it easy on the car (which is difficult to do!).
I have not had a chance to give it a good highway trip yet, but my best highway mileage was 22mpg. My old 328i would have got over 26 on the highway.
I know that the mileage will be worse when it is cold out, but again, my 328i was getting 18 or 19mpg at the same time of year.
I hope you're right, and that it improves with more mileage. I can't afford this!