How durable is this mattress over time?

It rates 7.7 out of 10 for durability. The firm surface sits over a 1,504-coil system in 13.75-gauge tempered steel with denser support foam, and a 10-year warranty backs it. To get the most life from it, rotate it head-to-foot every three to six months and keep it on a firm, fully flat base, since even support across the whole mattress is what prevents early dips and uneven wear.