My sister got pg with DE via a 34 year old but man was she proven (four boys). My sister had a boy BTW.
Meanwhile, my donor was 22/23 I think. She was proven. It wasn't about age with her but she was younger than most I guess. She is lovely natured and that for me was priority one really.
My boy has a lovely nature and so has my DH. My little fella may have the tendency to be quiet so I am encouraging him to be 'out there'.
good luck with your choice, best, THK