OSFA vs Sized nappies

I'm new to MCNs & am hoping to use either pocket or AIOs.
The thing I'm not sure about is whether I should get sized nappies or the one size fits all? Can you lovely ladies please tell me which ones you use & why?

Weused mainly OSFA as my babies grow big and fat very quickly and I didn't want them growing out of sized nappies so quickly. For example we bought a peapod when DD was 5wks old and by 8wks it didn't ft anymore. Since then she has been in OSFA and once she hit the large weight range (9-11kg) I did buy some trimmer or special nappies in a large.

I have a chubby thighed toddler and I have had problems with the snaps on OSFA (the ones that aren't being used) rolling out to rub her legs. Can't get a good fit with velcro OSFA either - rubs in various places.

Crystal boo - Try Bumwear OSFA pockets they don't use the 3 row snaps to adjust to one size or the new fuzzibunz adjusts with internal leg elastic! I know what you mean those extra snaps can be a pain

I've got haute, bumg, baby kanga & blueberry.
The OSFM tend to be a bit bulky on a little bub. Especially in the front where you adjust the pocket. Didn't like haute pockets due to that and am also not fond of baby kangas as it doesn't sit right on the one I have.
I have some BumG OSFM that are trimmer and have been in use for a good 2 years but they really are looking a bit rough. They still work fine but the velcro tabs have freyed and are pulling off so they will need replacing as well as the elastic. I chose to get blueberry pocket OSFM for Ruby instead. Are a bit bulky also but not too bad.

Something to consider is dragonfly magik. They are an AI2. I'm happy with them on Ruby though they are on the bulky side, but not really bulkier than the blueberrys. I have 3 and will hyena some more I think ;) Gigi put me onto them with her glowing reviews!

As for AIO's I like itti bittis and bubblebubs.

I started using MCN when DD was 3 months old. I bought Itti Bitti D'Lish snaps in medium and she was out of them by 9 months old, but I loved them so much that I bought a set of large and she is still in them now (17 months old). It looks like she'll continue to fit these for ages. At the same time I got some green kids pockets, however, I thought they were too bulky until she was about 10 months old. They are are perfect now but she loves to undo the velco:wall: