OMG Thirsties covers are FANTASTIC. I haven't had ONE leak. and jazz has some pretty wet and feral pooey nappies! The Target/Kmart brand of covers are pretty useless for terry flats. If you're going to go with flats you really kind of need to spend the money on covers. I don't mind Bummi's too, they are pretty much the same as Thirsties I have found. I get leaks with BBH PUL covers, they have no leg gussets, which is pretty essential us (not for everyone though ).