April 2006 I bought a Sterns & Foster Berkley (model) mattress at Mattress Firm (store). The first year was ok. but it began to sag in the middle and it is less than 2 years old. you can't lie flat. anymore. It get worse each month. I filled out the paperwork from Mattress Firm and mailed it in. I will call Sterns & Foster tomorrow. The piping on the edge of the mattress is fine on one side. The other side the piping is under the mattress, not on the edge. I spent over 1400 dollars for the mattress, box spring, delivery, and a new... read full review »