All subjective of course, I notice rattles in my E82 where others don't; but I'm not expecting any issues in my F30. Test drove one for the weekend a few weeks back and it was solid as anything, though the dash and interior trim parts did creak a bit more (just when pressed) than my E92 which you just couldn't get a creak out of; but unless you go looking for them, I don't think you'll have any problems
Dealers are usually pretty good at sorting them out anyway, at least mine has been in the past.