These are great. Our baby had tummy issues and reflux. We had to use a particular kind of formula. These reduced the amount of air she would swallow which was one less thing to worry about.
Given the extra parts in the bottle, cleaning them was kinda a pain as you have to use a little brush to get in the all the holes and blue tube part. You’ll need a dedicated drying rack as the parts can take up a lot of space. We used the microwave steamer thing to help disinfect them too.