I used them exclusively on dd1 and used them with a mixture of pockets, fitteds and terries with dd2.
I had loads of leaks with dd1 as i had the bambino mio system and the wraps let me down as they leaked and wicked due to cotton outer. The key is getting a good wrap. I love thirties duo and lots of people love the flips.
They can be more bulky between the legs than pockets or some fitteds and once mine have started walking I prefer something slimmer.
I would always have prefolds in my stash and as @jellybelly6 says the thirsties hemp ones are lovely too
very slim and absorbent and don t go crunchy... They do take a bit longer to dry having hemp in them
Hope that helps.