I purchased my bed through Mattress Firm. I have a full size Posturepedic Hybrid Norman 12" Mattress with this frame. There are times when I can feel the lifting mechanism in the middle of my back when raising the head of the mattress. I also find it very easy to hit the Zero Gravity button at night, when I don't intend to. They didn't warn me that I would need to secure the fitted sheet because it moves when sleeping with the mattress adjusted. And the sheets resting on my toes was very uncomfortable. However It was an easy remedy with sheet clips and bed blocks to lift the sheets. I just would like to have known sooner. I considered giving it a lower rating because of the mechanism jabbing my back being uncomfortable; but it doesn't happen all the time and overall I do believe I have been sleeping better.