I have found the above mattress to be a good product. I was a little apprehensive at first because coming from a worn out spring mattress to this was an adjustment for me and I did not get the type of sound sleep I expected. But after about 3-4 days, I had some of the best sleeps of my life since I stopped using my tubular waterbed 3 years ago. I think it takes a few days for your body and the foam to get acclimated to each after which the memory form gets accoustomed to your body weight. By that I mean it gets compressed in the same way and accomodates your weight and form.
I bought the firm mattress because I like that type of matress and I'm a big guy (6ft 250 lbs). Also because mattress that is too soft gives me back pains. In the first 3-4 nights I did not get the total restfull sleep I'd anticipated but every night since then it has been sleeping bliss. I'd recommend this product to anyone whose in the same category as I described above.
On a final note I was a bit disappointed by the Cal King Memory Foam Pillows that I also purchased. I had been shopping for this product for over 6 months during which I'd seen, tried out, and evaluated the designs of both the mattress and pillow. The other pillows I had seen/tried were either made of a composite of memory foam and some other denser foam in the core or had a sculptured shape that had a thickere portion at the widest side os the pillow to support your neck. These pillows were just a piece of memory foam cut into the shape of a standard shaped pillow (with the proper length for a king bed) that is thickest in the middle and tapers to a slimmer thickness at the edges. It wasn't very thick in the middle so when any weight was put on it, it compressed to thin profile that barely supported your head with any elevation. Though it sort of works for me since I prefer a flatter pillow, but I believe it might be an issue for other people as its barley supporting my head in the fashion I would have suspected, based on the other pillows I tried.
Of course once you open the package you cannot return the item, so I'm stuck with it, but I would have wanted to exchange it for a different type of pillow if I knew ahead of time that was the type I'd get. So I'll just have to chalk it up to dealing with the prevailing policies when you purchase through the internet.