2012 X5 35d - opinions?

[hibble]

Hello All,

I'm a long time BMW owner and I'm considering my first X5! I've come across a nicely optioned diesel example and wanted to get some thoughts on it. Here are the specs:

2012 X5 35D
51k miles
Sport
Premium
Comfort Access
HUD
NAV
Active Ventilated heated/cooled seats

I really enjoyed the car and especially enjoyed the low end torque of the diesel. Here are my questions:

1. Is a somewhat rough idle normal for the 35d? With A/C off and windows up and in Park I could feel a noticeable vibrations through the steering wheel.

2. How does the maintenance of the 35d compare to the 35i?

3. Any other thoughts on owning the diesel?

Thanks!