I got the chance to drive a 335d back when they came out, a friend of my father had gotten one. It was impressive for a diesel. If I had to travel a lot, particularly if it involved a lot of highway driving, it would be a near ideal car, offering a great combination of comfort, performance, and fuel economy. IIRC the thing was averaging around 33 MPG combined (back in 2010).
Also keep in mind my only other prior experience with a diesel car was a neighbor’s circa 2001 VW Jetta TDI, which I didn’t find particularly inspiring.