How long will this mattress last?

Durability scores 8.5, helped by its firm build. Support comes from 1800 coils of heavy 13.75-gauge tempered steel that resist sagging far longer than budget-gauge wire, under a thin, firm high-density comfort foam. Because the comfort layer is thin and firm, there is little soft foam to develop body impressions in the first place. Springwall backs it with a 10-year warranty; rotating it head-to-foot occasionally keeps the surface even.