Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Buyer beware

I do not believe that the product that arrived here actually was Serta brand. My husband has a Serta memory foam pillow -- it is of much higher quality than the one that arrived here (and has a tag identifying it as a Serta product, which this one notably lacks). His 4-pound density is much squishier and more comfortable than whatever this is. Whatever else it may or may not be, it is flat, uncomfortable, and gave me a headache the one time I tried to use it. I guess it's back to stealing hubby's!