This will be the best $*** dollars you will ever spend. As rated on sleeplikethedead.com, they were not mistaken and after a night's sleep on this mattress topper, it's understandable why it is the top seller. I received from Overstock using regular shipping in a few days. I carefully unwrapped it, letting the topper unfurl on it's own. We let it breath in a room with an open window for a day and half before putting it on our bed last night in order to give it a chance to off gas, which is normal. I was ready to put down $4,000 on a new Tempurpedic bed and had gone around trying out the Cloud, Contour, and other models. These mattresses boast the highest density foam of 4 lbs+. After reading all the reviews on sleeplikethedead.com of mattresses and mattress toppers we concluded that spending $*** first with a very good mattress topper made economic sense before spending money on a new bed. The topper is a true 4 inches thick. When I place my hand on it, it gives firm resistance before allowing my hand to gradually sink in to the dense foam. When you remove your hand you see the imprint for a bit before it disappears. This is a sign of a very dense memory foam! We placed this on top of a king size Select Comfort bed. Even with the 4 extra inches, our deep pocket sheets fit just fine. The bed is really tall now. My fiance and I both have lower back problems, her from being a flight attendant for 24 years, me from being a chair warrior in an office and being 200 lbs. As soon as we both laid on the bed with the new topper we both immediately became silent as we were overcome by the new sensation of lying down and feeling zero pressure points. I normally keep the Select Comfort bed at 45 to 50 on both sides but we wanted more support knowing that the memory foam topper would provide the softness and pressure point relief we needed so I put it up to 60. I could go higher to perhaps 75 because 4 inches of memory foam is more than enough softness. None of my limbs felt numb as they might ordinarily on a regular bed. I have a bad left shoulder and slept on it the entire night. I couldn't feel any part of my body as the whole thing was evenly disbursed over the mattress. I think my body was confused! My lower back? Nothing. Didn't feel a thing. Zero pain. At one point my fiance stole all the sheets in the middle of the night so I had to get up and move her over. Annoyed, I laid down and it felt like I just closed my eyes when I awoke to sunlight five hours later. I couldn't believe it! It was like I disappeared for five hours! My fiance was in a blissful coma when I awoke and just didn't move at all. I left her there for a few more hours. She awoke rested after doing a trip to Venezuela and Punta Cana that damn near killed her. Summary: Buy this topper now, knowing you need at least 48 hours to air it out. You will not want to wait any longer to sleep like the dead. As long as your existing mattress is firm enough and has a firm foundation, you should have no problem adding this topper to have an entirely new experience, giving your current mattress and foundation a few more years of life. (I guarantee that if and when we replace the sleep number, we will either re-use this topper or get another one.) Whereas I previously didn't care much about sleeping in my own bed since I'm on the road in hotels all the time, I can say beyond a doubt that I will be dreaming of my bed and getting back to it and into it earlier.