Just read the forum. Lots of threads on CBU and a few others fun things. The emissions system is complex, so there is added risk there. But there is risk in anything you do in life: a 335i that has pump/injector and other issues is no picnic either.
Maintenance is not all that different in all honestly: the oil is LL04 so a bit more expensive per change. Fuel filter every other OC. DEF is much cheaper to DIY using AdBlue or VW sourced stuff vs the very high markup at BMW (VW/MB/BMW use the same OEM for their DEF).
Hey, no spark plugs :P
I have a non-BMW extended warranty and will see what happens. Its a fun car to drive especially if you have some decent HWY seat time. I have averaged 33 or so for the past 15K I have had the car (second owner) and don't baby it accelerating in the open. No JBD for me either: its got more then enough to spin the open diff, especially in the winter with snow tires
- b