This was a great mattress for about 6 months. We flipped it and it slept good for another 6 months. After the second flip we notice low spots. It seemed you would roll into one or 2 people would roll into each other. The mattress is supported by 2 wooden boxes purchased at the same time. These required screws around the edges to stop the "quacking" sound between the wood and the plastic edge guard. Now after approx. 2 years we are waking up with slight lower back pain. This goes away after a bit but is obviously not a good thing. After reading the terms of the warranty there is without question NO need to contact either the merchant or the manufacturer for a replacement. READ THE WARRANTY..I doubt you will risk your hard earned money under these terms...