Shifman Mattresses have been known to last ten years plus. Shifman Mattresses are one of the few mattress manufacturers that still makes two-sided mattresses (which extend the life of the mattress while maintaining its comfort level and firmness).
Because Shifman Mattresses feature an eight-way hand-tied boxspring, the hourglass coils they use provide strong flexible support and durability. Their hand-tufted method produces a smooth, buttonless tuft that eliminates shifting and bunching by interlocking all the layers of the mattress.
It takes anywhere from 7 1/2 to 12 1/2 hours for the artisans to actually build the mattress.
They only sell to high quality furniture stores... Small local high end furniture stores and Bloomingdales.
You should contact a local dealer and try it.