If NB Bs are eyeballing both, flying the 330 as an F/O preps them well for 320A (the airplane…not the lifestyle!). I have also run in to people who have flown both and prefer the 330 over the 350. Sometimes it’s the button-pressing (everything seems to take more ‘keystrokes’ in the 350), and sometimes it’s the bunk.
Since there’s a rumor we could pay band them together, there’d potentially no longer be a pay difference.