I went from a 2007 328xi to an 08 M3. There's no comparison. The chassis alone is night and day. The engine and trans combo is bad ass. It takes being in any given driving situation to really understand how these things deliver the power to the ground. My 328xi with big tires handled great. But the M3 goes through corners with ease and carries much more speed. It's the big dog, no question.
MDM kicks ass. Set up your M button to include MDM and your key dependent settings up from default.
I'm still giggling and spouting expletives in the car when I drive it. Holy crap, etc,.