If you do a search for posts about mattresses, I will bet over 80% will include the words "memory foam" in the body of the post. It is my guess that Heartland got a special deal on mattresses when Siberian work camps were shut down. Seriously though, in the ultra light RV lines, most manufacturers are placing the priority on weight reduction, so thinner foam mattresses make sense. Not to your back, but to the manufacturer. We also went the memory foam route on the queen mattress in our Edge. Check the the thickness and quality of the memory foam carefully. We found a big difference between the WallyWorld memory foam and the Costco type mentioned above.