I checked several local mattress stores and priced memory foam mattresses. I found this mattress and decided to gamble on it because it was a good value compared to what I was looking for in the stores. We have a split King bed so I purchased two of the XL twin. Delivery was prompt and the mattress were in two fairly small boxes. We opened them and they immediately began to expand. In a couple of hours, they expanded to 12". They also did not have any strong smells. We slept on them the same night and they are wonderful. Medium firm comfort that lets you sink into the mattress but still has a firm hold. Old spring mattress would cause night pain in my hips but this mattress does not. For me, this was a great purchase.