Bought the Serta Perfect Night King Size pillowtop mattress and its been dipping at each side where the bodies sleep and a hard lump like a mountain in the middle. Reading all the reviews I knew Serta would do nothing about this so I went about fixing it myself. I cut off the pillowtop and threw away the stuff they had put in there and replaced it with a Canopy 4" memory foam topper from Walmart ($149) now its good to go.
If you want to do this its so easy. Cut along the top seam of the pillowtop all the way around. I used a box cutter. Once you do that you will see that the top layer of the stuffing is glued around or sewn around the quilted top just rip it away too. Take it down to where the mattress starts and you throw everything above that away and replace it with your 4 "memory foam mattress topper. When you see whats in there it makes you wonder why they charge so much for mattresses.I say a 4" Topper because when you see the depth of the pillowtop its about that. I will never again buy a mattress at the price I paid for the Perfect Night. I think you could lay a memory foam topper on concrete and it would be great!

Bed was bought in Feb. 2010 and began sinking in six months. Serta rep came out and advised over two inch sag and box springs were shot. This was our second Serta in two years. Will never look at another Serta bed. This was their top of the line.

I purchased the Perfect Night Catalina Eurotop and was so excited after trying two other mattresses with no luck. I thought this is it... finally! Boy was I wrong. My first night I was in heaven, went right to sleep. Night two my back/hips were sinking down so low it caused major pain in my back. There is absolutely no support in this mattress. After 3 nights we rotated. We found that the material on the box springs was not sewn on very well and the seams were coming out. After rotating I had one more night of good sleep and then I sunk again. Another thing I hated after trying a Simmons was that I felt every little movement and kept getting woke up at night. I even felt the bed vibrating a bit when our furnace came on. I called today for my refund. I am now in search of yet another mattress. I think I'm going to an old fashioned flip mattress and adding my own topper. This is crazy.