I love this for so many reasons... the recessed middle "feet" and the rounded corners for the four major "feet" and the sturdiness. Now here's why I can only give it 3 stars... we put the twin mattress on top of the frame, and the mattress slides. It doesn't stay in place when someone sits on the mattress. It slides. Perhaps a double or queen mattress would be heavy enough not to slide. I don't know. So we took three 2 'x 3 ' floor rugs and covered the top of the bed frame with them. The rugs have non-skid, rubbery, bottoms and a raised, sculptured pattern on the tops. Now, the mattress lies on top of those rugs, and it doesn't slide at all. We had those rugs already in a hallway, so we tried them as an experiment, hoping that they would secure the twin mattress. They work. So I'm happy to share a solution that at least worked for us, in case someone else has purchased a twin size frame where the mattress just slides.