The worst mattress I have ever had was a Sleep Number bed. All of my mattresses in the past 15 years have been queen size, except for an electric hospital type bed (bought that so I could change my position without getting up). The sleep number air bladders were separated with a soft foam strip in between and I always ended up in that "hole" in the middle without any support, worse for my back. A friend also had the same problem with his and he got rid of it, too. After MANY THOUSANDS of dollars on mattresses, I have had Sealy, Simmons, Stearns and Foster, Somma Supreme with water tubes, and tried a few others in the past 15 years and they were all in the higher bracket, not the low end cheap ones. About 3 months ago, I bought a SERTA with a memory foam, though I think I needed one a little more firm, it has been the best. My son and daughter-in-law have a Tempur-pedic and love it, and my neighbors love theirs, though they all said it takes a while to "break in". I just didn't want to spend the $3000.
Interestingly the BEST INVESTMENT above and beyond the mattresses, was the NUTRITION that truly CHANGED MY LIFE with the back pain. I had dealt with back pain due to failed surgery, spinal stenosis, degenerative disc disease, multitudes of injections, therapies, traction, and way much more....long term disability...NOW no drs. no meds, no disability. If it were not for my Nutritional Products, NO MATTRESS would have made the difference on my back.