I know I am 'late' to this thread; just got around to reading every post...
I sleep on a kingsized, solid latex foam mattress, made by ENGLANDER. It is still in VERY good condition(no kids ever slept in it; no 'stains', if you know what I mean!) It was my mother's, and it is 'about' 35 (or maybe more!) years old! I inherited the entire kingsized bed from her after she died in 1979; she was the only one who'd ever slept on it, as she and my father had slept in separate bedrooms for years before they divorced after she found out she was terminally ill (long story, but something she should have instituted years earlier!) I
Yes, it has 'sunk' just a LITTLE bit on each side (when you get over in the center, you can 'feel' that it is a bit higher!!) That said, it is still quite firm and comfortable! I DON'T get up w/ a backache (and because I am the sole caretaker of everything on this place, I do a LOT of HARD physical work, almost daily--and I still get up with my back feeling fine!) AND, this mattress CAN be turned over! Even though it's only about 6" deep, it is VERY dense, and therefore, heavy,and it takes ALL I can do to turn it, but it IS 'doable'. This bed also ISN'T so high(Neil was so right about that; modern beds do seem to need ladders!
I imagine those reading are aghast at this; all I can say is...I wouldn't still be sleeping on that mattress if it weren't comfortable and I was having ANY kind of 'bad effects' from doing so! It was a top of the line mattress when my mom(who was an interior designer) got it, and this is the proof, IMO!! And I will admit that I am appreciative of how well it has lasted, as I have PLENTY of other things that 'stand in line' needing to be done, and they ALL cost more nowadays!!
Jayne, sounds like you made a good choice for now!
Margo