Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Like sleeping on a sack full of rolled up socks

Title is not strictly accurate -- no one has actually slept on this mattress yet, nor will they ever. It is barely tolerable on a futon in "couch-mode", but as a bed it is lumpy and you can feel every contour of the futon slat through it. I wouldn't subject any guests to this mattress, at least not guests that I like. I would strongly recommend avoiding this product.