I purchased a Serta Mattress 5 weeks ago. After 2 weeks, noticeable indents began showing up in the mattress . . . it has a worn look already . . and is already sinking in the center. The rep for Serta came to my house (Darrell) and told me it was normal wear for a mattress. He said it is only sinking 1/4 inch NOT and in order for the warranty to be effective, it has to be sinking 1 3/4 inches. He told me to turn the mattress ever 2 weeks. (i am 72 years old). I am not a big person. Less than 140 lbs. I sleep alone. Thi... read full review »