Probably also worth taking loads into account.

Love the UD but it's likely going to be pretty full on most late evening flights. I know you asked about hard product but full cabin will mean lights off later (though sleeper service means reduced light even during "service" and more traffic throughout the cabin.

318 loads used to be lighter so (unless things have changed) you have decent chances of not having a neighbour and less traffic in the cabin (my only 2 experiences had less than 10 pax with 3 crew which felt great (but that was 2 years ago)).