Yes I did use the covers for the BBH. Sometimes the explosive newborns poo would go out the legs of the nappy - but the cover caught it. That's the advantage of nappy + cover for a newborn. If you get BBH, you will be able to use them for your DD now + for the newborn.

I did use some terry flats for DS when he was little - but they only lasted for an hour or so between changes & they were so bulky! If you are going to go for flat nappies, I think the bamboo prefolds are going to be a better bet.

But, I like the convenience of not using a cover (which is why I like the greenkids!). I think DS was using these from 3-4 months - but he was a porker. He was 8kg by 3 months.