I had a total of TWO PUL covers with Zeke lol
yep, just two. Can't remember if they were Bummis or Rikkis but either way they rocked
that said there are tonnes of new ones out since then so...
Zeke (only 7lb14oz) started in smalls, he went to mediums at 5 weeks old

(Jake would have been in smalls for yonks tho and Brooke was average so prob smalls for standard time)
BUT I think generally speaking smalls are a good option.
oh and more than two

and I never had a poo explosion, ever with Bummis/Rikkis.
After those I went on to make my own
and later tried all manner of covers lol
Pre MCN I only used Fluffies supermarket covers for Brooke, and then later PVC for Jake.