Beautyrest review: Worst mattress that we have ever purchased

Within a few months the king mattress started sagging. Complained to Beautyrest Warranty division - they blamed it on support - we quickly remedied what they considered an issue (even though it had never been an issue with our 15 year old mattress that we owned before) - now, 18 months later we are taking the $1,500 mattress to the dump. Deep sags on both sides - huge hump down the middle of the mattress - feels like your body is sleeping in a hole. We wake up each morning with extreme backpain. Beware of purchasing a mattress made by Beautyrest as they do not honor their product warranty.