Okay, let me start by saying these bottles are a GAME CHANGER for my colicky little one. The anti-colic system actually works - we've seen way less spit-up and those painful gas episodes have decreased dramatically.
The slow flow nipples are perfect for my breastfed baby. She transitions between breast and bottle like a champ now! Though fair warning - cleaning all those tiny vent parts is a bit of a pain (I've lost count of how many times I've washed the green insert by accident).
Love that this set grows with baby - we started with the preemie nipple and just switched to level 1. The included pacifier was an unexpected bonus that our baby actually accepts (miracle!).
Only downside? They can leak if not assembled perfectly. But honestly, the benefits outweigh this minor inconvenience. Worth every penny for better sleep (for baby AND parents)!