I purchased a Denver Mattress branded Madison XL queen size mattress at the Burlington Iowa store and within the six months that I've owned it and it has become unsupportive and the sides are not firm and sturdy as they were upon the purchasing of it. Now needs to be replaced as it is total junk and I'm couch sleeping. The store in which I bought it will not replace it nor offer a refund. User's recommendation: Ummmm, no.