For the record I like the new 4 cylinder turbo engine and I currently own a N54 twin turbo which I think is one of the best engines BMW has ever produced. It sounds great and can put engines much larger then it to a shame. I was very much a NA guy before I drove the N54 twin turbo.
I think the difference overall has shrunk between the acceleration when you compare it against the previous 328i vs 335i. The new 328i is plenty fast and offers good gas mileage.
However, at the same time one can clearly see that the 335i is still faster and the difference becomes huge with rising speeds. None the less I am really liking the new 4 cylinder.