After promising a 20 year unconditional warranty at time of purchase, I now find out that after 5 years a new pillow top must be purchased to correct the sagging in the mattress. They claim this is normal wear and tear that is not covered under warranty. I see many complaints of this online along with mold concerns with the mattress. Sleep number is obviously not concerned with past customers. Know if a class action suit??? Count me in! read full review »