For what it's worth, I frequently wear both the small Abena S4s and the M4s and to me, they seem to be the exact same product, just one is smaller. It used to be back in the day that the smaller Abenas were shoddier but now, to me they appear to be of the same quality/thickness. etc.
Anwyays!! On the top of Bambinos - I ordered a couple bags of the classicos which I haven't in quite a long time. I was very disappointed to find that the plastic backing is the same rough, almost clothlike plastic that the Bellissimos originally were. Someone had told me that the plastic had changed to a more plastic-y, smoother feeling plastic like the Bellissimos had, but either they were wrong or I got an older product? Anyone know. I'm so bummed. I HATE the plastic!!