Greenkids are one of my favourite nappies at the moment. My son is 4 months old, and they fit him really well. I'm guessing that they would fit a newborn OK, but, as Anna said, they would be quite bulky.

They're not my first choice for overnight (I love the Baby Beehinds Bamboo with a PUL cover for that), but I have used them overnight and stuffed them with a hemp insert PLUS a microfibre booster, and it withstood 12hrs worth of overnight wee without leaking or wicking.