We bought the same mattress 6 years ago, and we're overall pleased with it. It was a standard king-size firm bed. It started to sink where my back began to hurt. So, we purchased a new California King in the firm. Within 2 weeks it began to pit at over an inch.  I've called the furniture company I purchased from and waiting to see how they will rectify this problem.  Maybe that it's a California king is the problem. We hope to go back to the standard King firm. I'll update the review later