Flips, hands down. Best borrow don't stretch at all and seem very uncomfortable and are a bit hard to find a good fit IMO. Flips, on the other hand, are super stretchy. The exposed PUL Doesn't seem as hot as the BB either. Plus, until next week, the covers are still on the buy 2, get 1 free sale, so they are way cheaper right now.
Mom of 4!