Exactly what we needed.  We both suffer from arthritis pretty much everywhere and were finding our mattresses that came with our VERY expensive adjustable beds just weren't doing the job any more.  I wasn't too sure how these mattresses would work with the adjustable mechanism, but it turns out, with a mattress pad that covers the whole thing as one, it works perfectly!  We both still sweat on and off, but I can't blame the mattress pad.  I blame the ridiculous amounts of meds we're on for our various old age alements!