I read that you should avoid polyester foam or rayon center inserts in PFs. I have been looking at GMDs, Imagine Smart fits and Diaper Rites and I can't find any info on what the center insert is? They all just say 100% cotton. Does anyone know anything about this? And on a side note, which of the 3 above would you go with? And another side note. Don't you think 30 Newborn PFs is alot? I mean, I thought babies grow pretty fast. I would think less newborn and more size small, no?