DH and I are debating between 4.0 and Freetime. Do you use BumGenius diapers? If so, which kind, how do you like them and why? We want to take advantage of the current CottonBabies sale...is there anything 4.0s can do that Freetimes can't? From what I understand, you can use extra liners in either for heavy wetters/overnight. Thoughts?