Has anyone used this mattress? It is a memory foam mattress. DWR is having a sale and I am thinking of biting the bullet and buying the bed and mattress. Even on sale, these things are expensive, but I have been looking for two yrs. now and keep coming back to this bed.

I'm currently sleeping on an old boxsprings mattress and it is too saggy. I pulled a muscle in my posterior rib cage (not sure how) but woke up three weeks ago in terrible pain, so I think I did it at night. I keep waking up with the pain, although it is lessening, and I cant help but think that this saggy mattress is not helping things and it's time to get a new mattress.