Why not do away with spring and mattress thickness issues all together and get a water bed?

Water beds take getting used to, feels like a whole new experience when sleeping.

not sure i would trust the floors to take the weight in some apartments. a 150 bed holds over 700 liter/kg of water, + frame headboard heater mat etc. and two people, maybe another 200kg. small footprint, only a little of the weight next to the wall

Have not had any reason to expect any collapsing floors in Kunming, but maybe I just don't know.

at 2 people 200kg any regular movements may not make the floor collapse but most probably start an earthquake, or tsunami if it's a water bed

I'm selling a thick latex mattress, like new, always been convered, 6 months old, 1800 X 2000 big size :-) :-) it's a brand one, 1200 ONO (less than half price)

I think many waterbed partners are, in fact, there for the tsunami.