My 330d is a 6 speed auto and it's so smooth. The car is on 85k so the auto box could do with a service fairly soon. I know the oil for them is really expensive.
Just driving normally and sometimes you can barely feel it shifting. I'm hoping when I get it serviced it'll be even smoother. I do find though that driving in manual and using the paddles to shift, I can drive it even smoother than in full auto.