I purchased this in the middle of august, now the beginning of January and the mattress hurts my back. It seems to have lost it's firmness greatly. At the beginning it was fairly firm, then it broke in a bit and was excellent. Now every morning I wake up with a painful lower back because I sink in too much. Very unsatisfied with this product since it should last more than 4 1/2 months. I even rotated the mattress pieces several times throughout it's life time with us. Bottom line, don't buy this product, spend the extra and go with something else.