I bought these bottles first but my daughter was unable to use them. Unable to get her mouth around the nipple properly. Had to go with a smaller nipple.

These bottles are a bit on the pricey side. My new daughter in law uses these for my 3rd grandson. They seem okay. He's on soy formula, so he doesn't need a lot of air in his tummy. So far, it doesn't seem like they let air in and he seems content.