Hi Ross,
Like anything everyone will have their own views on different makes & models of cars...audi v bmw, merc v audi, scooby v evo.....you get the idea.
Best thing to do is give any car your thinking of a test drive and then do the necessary research.....
All I can give is my experience of things,
Have been daily driving bmw for over a decade....320d x2 ,then on to 520d x 5.
Yes the timing chain is a costly fix ,but depends on year of car you be looking at....if done ,problem solved.
I don't hang on to cars usually past the 2yr mark but in all my time the only beemer to give me an issue was a 191 520d with 25000kms on the clock.....kept going thru oxygen sensors,......adblue wasn't a help by all accounts.
I moved to the 1.6 Golf..lovely car to be fair .only reason I moved the golf on,After big auto ,saloon cars I just found the golf small....530e is only in my possession a week so can't comment on that.
I'm only putting forward my experience on both and hope this is of help to you.....
If you want any other info ,feel free to PM me