We have two of these covers in our stash. I like them, they definitely run larger than my BB and Thirsties size 1. They did fit our large newborn when he was 11lbs without leaks, however, I just had to make doubly sure the leg holes were cinched tightly. I'm sure that these will continue to fit much longer than the other brands, especially since my children are usually large for their age.
I really like this cover! It seems comparable or nicer than my flip covers. I've not used it on a little one, but they work great on my almost 2 year old!