Second BMW (first being M3). Purchased pre-owned. Love almost everything about it. Has just about every possible option and package. Love the 19" wheels. Did have to adjust driving some to accommodate for brake assist and trans system. Once I have done that, it is fine and very enjoyable to drive. Do not have problems others have mentioned. Just took a judicious right foot. Very comfy sport seats and great thick M-sport steering wheel. Now that we have a baby, it is perfect. Not my M3, but a good compromise for the time being.
Build quality. Nevada leather covered sport seats are fantastic. Engine... typical BMW greatness.
Better imaging on stereo w/ 6 disc standard. Bass is nice, but need better tweeter placement. Better gas mileage and slightly bigger cup holders (although better than my M3).