Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Bad Experience

I bought the Avent bottles with the best of expectations. The first sign of my let down was how bad they leaked. If you screw the lid on too tight, they leak and you have to loosen it so they won't. I recently discovered that my son's trouble eating was also due to the large size of the nipples. I switched to the the old faithful, Playtex Nursers, and he's eating much more relaxed and much better now. I can't tell you the difference. The nipples are just too fat on the Avent system.