Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: A poor quality light, both the light output and durability

I have purchased a set of about 50 TCP R20 14 Watt bulbs to replace all of my incandescents. After about a month, a quarter of them burned out after a normal use - about 4 hours a day. The light generated by them is cold and harsh - in spite of 2700K rating - we find ourselves not wanting to turn them on. I am about to replace them all.