The one thing I found with the air mattress is it changes pressure with day into night use.
I would pressure it up nice and firm just before going to bed and later on at night when things cool down around it loses it's pressure and we would sink into the air mattress.
I went back to the original bed mattress and added three inch magic foam on top of that. This worked out great for us.
However then we found out the properties of the magic memory foam toppers has a drawback to live with as well. It seems when the temp goes down around freezing the memory foam items get hard as a rock until the temp goes back up... Was very strange the first time we found our memory pillows hard as a rock...
Roy Ken