Poor durability, poor warranty

Great the first one to two years, then began having sagging issues and developed a large ridge in center. They measured the sag for warranty but said it didn't meet criteria. The measurements were taken closer to the center and not where the main sag was. For nearly $5000, I would have expected this mattress to last well over 10yrs. We have had it now for 6 and have suffered long enough. Going to try a tempurpedic or something else. As a side note, neither mattress store in our area stocks this mattress any longer. They both related too many problems and poor company response.