We have had a Sealy Mirrorform memory foam mattress for about 5 years. In the last 12 - 18 months it's totally lost it's supportiveness around the lower back/hip area and consequently I'm having really bad lower back pain that stops me sleeping and makes me sore and stiff all morning. I know it's my bed that's causing the problem as when I'm in a different bed the back pain disappears. I've seen both Tempur and Ergoflex mattresses recommended, but many people have reported similar long term problems with Tempur mattresses (and they're way too expensive to have to replace every 4 years!). Has anyone had long term (12 months+) experience with an Ergoflex mattress?