What is a better car to have a BMW 428i gran coupè or a BMW 328d x-drive?

An Acura, Lexus or Infiniti would last longer and be more trouble free.

I test drove both and went with 428 GC xDrive. The 3 felt a touch lighter and more responsive but I am second guessig that impression even as I am writing this. GC won me over with its looks. It also felt cozier and quieter inside and I loved the trunk capacity provided by the hatchback. I also agree that if you are over 50 and care about reliability more than fun of driving, get Lexus or Acura. I would stay away fron Infinities though. I don't trust Nissan.

328d x-drive for fuel economy and reliability (iron block diesel engine, the electronics will go before the engine does) or 428 GC for aesthetics. I personally would go for the GC, much nicer looking car and what the 3-series should have looked like in the first place.

Yes go for the Japanese counterparts if you're looking for reasonable reliability and don't care about the lack of soul, and don't mind the odd squeek and rattle and wind noise as the vehicle ages....