Velcro will wear out before snaps . The two main factors are price and preference. Fewer sizes are needed. Prefolds dry the quickest. Fitted diapers fit just right on your size baby.
Snaps provide an easy, adjustable fit that is just right each time.
No diaper cover is needed for those hot days or when diaper rash is present. No pins needed. Works great with an Aristocrat Wool Soaker. Proven to be the best leak-proof system when combined with a Bummis Whisper Wrap or Super Snap cover. No, you do not have to use all of the same type of diapers.