I have driven the E92 335i with the N54 motor on two occasions. In short it's a monster! The torque is disgustingly addicting, especially because it's so readily available from low rpm's. The first time i drove it I could have sworn there was a smidge of turbo lag, but after a little more extensive driving that notion proved false. What I loved most about the N54 was how user friendly it is, it could have been a brutal motor like what you'd find with the S54- surplus of neck snapping revvs abundant(or was that SMG that was doing the neck snapping??? :iono:
)- but it's quite smooth and responds with such an immediacy that sometimes you think you're driving a GT as oppose to a sports car. I think those of us expecting the 135i to be aggressive engine response will be pleasantly surprised but not disappointed by it's smoothness. BMW has pulled a hat trick w/ the N54 by making it a swiss army knife, or an engine with a dual personality. - Getting excited just writing this all up!!!!!