I have king size Sealy Springfree Beachside mattress and have very disappointed with it. It has sagged (body impressions) and is very uncomfortable causing poor sleep and achy back muscles.

Waste of money -- thought I was investing in a good mattress and it sagged fairly quickly. I've been living with it for 4 years now and must ditch it.

I did lots of research before buying a latex mattress. It doesn't keep us cool as promised, and it started sagging within months of purchase. We had the indentation in the middle of the bed measured by the company we bought it from, and it measured 1 inch of sagging. The way they measured this was very unscientific. To get a replacement, the indentation needed to be 1 1/2 inches. Very disappointed in the longevity. We are still sleeping on it three years later, and I need to find a mattress that doesn't sag like this.