I prefer the sewn in right now - I put the snap in one today and I matched up the coloured snaps but the trifold insert didn't seem to sit right for some reason with the other bit that goes over the top = not sure what Im doing wrong.
I prefer the sewn ins because my little Jett man has legs that are too skinny for the snap-ins. leaves him with too much leg gape and far too much poo escape for anybody's liking!!

Tan - I found that the first time I used the IB snap in, so spoke to IB and they explained that it sits funny when it isn't on baby, but when you stretch it to fit on to them they sit properly! I am glad I am not the only one that found that!

Ooh, Gigi - I can't remember my criteria either, but I think it was AIOs other than IB that have a low rise, narrow crotch without the suedecloth inner.