Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great at first but......

This was the best airpot (stayed hot for about 24 hrs) I ever had then after about 10 months of use, it must have lost its vacuum seal somehow, it was always handled with care and never dropped or anything. Now the outside steel shell gets very warm when filled with hot coffee, which means it is losing heat too rapidly, cooling the coffee, after about an hour and a half the coffee is room temperature...BLAH! Typical of chinese products they look really nice but they do NOT perform/work for anytime greater than a short period of time. I have a glass lined thermos carafe which is about 20 years old which still works great!