Another issue is that waterbeds last too long . That's right, they last too long. The typical innerspring bed starts wearing out almost right away. Just like the shock on your car, the springs start compressing and the cushioning materials start breaking down. The cheaper the bed, the faster it wears out.
Large people can end up with a badly sagging innerspring mattress in as little as two years.
Our waterbeds sleep almost as well ten years later, as they did the first night.