I ordered one of these knock off memory foam mattresses in late 2008 from Overstock. I would strongly recommend avoiding buying one of these knock-off brand memory foam mattresses. At first; during the first 7 or 8 months, we loved our mattress. But, after about month 9 the mattress developed deep ridges where my wife and I sleep. We are small people by the way.... I am 5' 9 and 165 pounds. We both started to develop shoulder and back pains. The knock off brand mattresses tend to break down quickly and don't bounce back to the original firmness. So... after just 2 years; we got rid of our mattress and bought a Tempr-Pedic and absolutely love it. I just felt compelled to write a review to warn people to save their money and buy the real thing because these knock-off mattresses do not last long at all... at least, this was my experience.