The M3 sedan is an excellent all around performance car. I traded in an RS4 for this car and have no regrets at all. For me the M3 handles so much better than the RS4. It also delivers power better, sounds better, shifts better and scrubs off speed better. It corners like a car weighing 600 pounds less. The exhaust note sounds fantastic, like a proper V8. The steering can feel a bit numb but once you attack a corner it comes alive and you know exactly what the front tires are doing (unlike the RS4). The car is a real hooligan and blast to drive. Poised and well balanced, I think you would be hard pressed to find a sedan with the same attributes for the money.
Steering, acceleration, engine, shifter, balance, exhaust note, sport button, deceleration.
I have owned other BMWs and this one seems to have the cheapest interior. The gauge faces look like paper cut-outs, the interior lights do not offer enough light. I also would like folding rear seats and fog lights as standard. But really this is nitpicking.