Thanks - that link makes some sense but I did find this from other one from Phoenix - post #3 and since I am overweight I worry. So now think I really should blow the budget and go for latex core. BB’s full latex is 10" and then other posts saying go for thicker mattress if overweight. I tried Original Matress 9" and 12" at the store - the 9 felt just a bit soft with a traditional box spring. I sunk into the 12 too much for my tastes so I assume I need firmer if going with thicker.
I’m overwhelmed by all of the info so please excuse me for rambling.