The most slimline I have are the flips, but I rarely use them as they have a reusable outer and then you just change the inner, allegedly, but any poo that happens means a change of both layers a lot in my experience. My go to nappies are BumGenius 4.0, I find them not too big and very reliable. However, everyone I know that does reals have different preferences, it's as much about the baby as the nappy, so I would suggest only get 1 of any that you want to try, then once you've used them a lot, make a decision. I am another nappy addict though, have about 10 types! Enjoy, it's a dangerous addiction :0) xxx