I have replied to you on the daily thread but will post here too.
I think mostly people prefer pockets to aios because of the lack of flexibility in absorbency (you can add boosters but that sort of defeats the object of an aio) and the length of time they take to dry as you cannot take them apart.
So if you are prepared for those things then I have actually been hearing good things about aios lately (especially the Bumgenius aio).
Absorbency is never a big deal with newborns but I am not sure how good they are at poo containment. I have only really heard people talk about Magicalls on older babies, certainly don't know anyone who has used them in XS. So you could b e a guinea pig