I've tried these memory foam mattress in the past and they don't work for me. My bones ache terrible when I lie on them. I have to have an air mattress but I'm so tired of the air mattresses developing leaks, so I tried this one. I love it. I've never hurt, not my bones nor my back, nor my neck when I've slept on this. I'm so glad I purchased it. No odor and I didn't even let it sit up and expand, I just put it on the bed and that night slept on it. I'm more than pleased!