My husband and I spring for a new pillowtop matterss from serta. Paid over a $1000 . I n 18 months it had sagged over 11/2 ins. They replaced it and we got one supposedly a little upagrade. Cost a little bit more. Same thing. We are looking for a really hard matteress but like you don't know what to get. We are thinking of the number bed so it is good to see so many who are pleased with it.