For folks asking about rear-facing center section seats, and which are best:
Wife and I just finished 10 hours in row 1, followed by 15 hours in row 5. (It’s been a long day/night, and still not done). Last year we did row 3. I did not notice any difference between them at all (crew noise, bathroom proximity, etc).
DISCLAIMER: Just my 2 cents. YMMV.