Replaced my Serta mattress after 13 years ONLY because of all this hype about replacing after 8 years. I am so sorry I did because this mattress is terrible and I do believe I am going to have a genuine problem trying to either return it or replace it because of the stingy warranty they give you. My previous Serta had a 20 yr warranty! This mattress "creaks" for starters. the main issue with this mattress is it sort of makes a "mold" of your body after a short time of using it. When I try to move to another location on this mattress it's like climbing a hill, not achieving it and rolling back into the "molded" area. So here I have this king size mattress and I am confined to this one small space which has outlined my body. I am so sorry I purchased this!!