After just four months we've got deep indentation where we sleep, and we're light weight. The center of the mattress seems to have risen up as a result of the bad support where we sleep. It feels like we're sleeping on a lumpy futon without proper smooth support. What a horrible mattress! What a waste of money! Retailers will tell you it's a good mattress, but it's garbage. Read the reviews of the owners and understand that you should run away from this Vispring company. Don't even consider buying a mattress from them. We bought the mattress because it contains no foam, but never expected such a bad feeling mattress.