The mattress is amazing. It's the BEST $600 I've spent. It could be due to the fact that I'm so used to sleeping on really bad, cheap mattresses, however, i really do feel the difference on my back. I currently have a bad back because of soccer, so my injury has taken a toll on my sleep. This mattress is extremely comfortable and you sink right in perfectly. I feel like it adjusts to my body and even sleeping with my boyfriend it doesn't feel like it's wearing down. I got the basic mattress in Queen size, and it gladly fits me (a 5' and 130lb girl), my boyfriend (a slim/tall-ish man), and our 6 month old pitbull!