Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Bottles leak... infuriating!

The bottles are great except for two things: (1) Too many pieces. God help you if you forget to put in the little blue ring before you shake. (2) This is the killer: Even when correctly assembled and tightly screwed shut, these bottles leak about 1/3 of the time. It's so infuriating to shake the bottle and have formula flying all over the room. I must believe there are better bottle designs out there. These are severely flawed.