Wife and I bought a sleep-number. I like beds super-firm. In college I slept on a wooden board, with a heavy blanket over it. That kind of firm.
Their 100 setting is pretty firm, could be even firmer for me, but is OK.
You can adjust it by sides
that’s nothing, I slept on a cold concrete floor and used my shoes for a pillow...
then I sobered up and they let me go home!