Aaptive M Sport Suspension is a must on the F30. I did a back to back comparison yesterday of M Sport Adaptive vs M Sport Passive Suspensions.
Without the Adaptive Suspension, the BMW does not feel communicative or connected with the driver. Without Adaptive Suspension it happens to become a lower grade of car.
We've owned a C Class 350 CDI AMG Sport with Adaptive Suspension before purchasing our two F30 330d M Sports. The BMW is the better driver's car but only when specc'd with Adaptive M Sport Suspension. As far as Engine and Gearbox are concerned, the BMW simply trounces the Mercedes with utter ease. The A4 is an anaodyne drive and not in the league of the BMW or Mercedes IMO.
Shameless plug: The UK Forum is full of interesting comparisons and discussions on Adaptive vs Passive Suspensions, on VSS vs SS, on DAB vs FM!
See below for Adaptive vs Passive:
http://www.f30post.com/forums/showthread.php?t=801767