We love this mattress! I don't know why we waited SO long to purchase it (a mystery to me??).. We bought a top of the line Simmons Beautyrest mattress set in 2006 for over $3000.. The mattress failed after 4 years. We went directly to the Simmons Manufacturer and had to prove by "photo measurements from every conceivable angle" that this mattress was indeed unacceptable. (Permanent, deep indentations in the pillow soft top), which sunk down deeper every tine we got into bed.) We are both average built adults, NOT big people.. Finally, Simmons replaced the mattress, for a fee.. About 3 years later, the mattress was already pathetic. We stuffed foam and anything we could find to fill the ibdentations, until we simply couldn't put up with the miserable backaches each morning. After investing HUGE $$$$ I ordered this wonderful memory foam mattress from Great Offer Stock (*). W/Free Shipping. I called Habitat for Humanity and they toll away my $3000+ mattress. No more backaches with this memory foam mattress😊. We set it up directly on our twin box-spring foundation (from the Simmons Cal-King set).