Rita needed a hard bed, almost floor hard.
I'm a spinner in bed starting on my face and rolling to my sides and back throughout the night. I also prefer a softer bed.
Rita came with a hard queen sized bed with a board under the mattress. I had a soft bed with a feather bed on top of that.
So we kept the hard bed and pitched the older soft bed and bought a sleep number bed. California King sized.
We only bought the mattress and the cheapest pump. We didn't have the numbers, just the pump remotes. So we don't know our numbers. She just kept hers pumped up and I'd adjust mine until I was good. We also didn't buy the plastic "box springs". Just the mattress and pump. That was around $650 total. I built a box myself for that.
In general I think it works well for folks with very different requirements.
When Rita left, she took the hard mattress set and I kept the sleep number bed.
By myself, I found I would migrate to the center foam which didn't happen with Rita and doesn't happen with Jeanne. I bought a body pillow to put in the center which does keep me from migrating to the center.
Jeanne also has a harder queen sized bed which was also uncomfortable.
As to humping, Jeanne and I don't really find the foam center to be a problem and actually find the softer center helps with leverage.
Carl