So I went out looking for mattresses yesterday. I did try the adjustable frame just to see with no intention of buying it. I’m hardly a decrepit old geezer. After trying it I thanked God that I was a decrepit old geezer and was able to justify buying it.
Thanks for all the replies.

I’m glad you tried the adjustable frame. They really are a game changer.
I’ve got no current opinion on mattresses, other than that I’m content with my mattress I got from Aldi a few years ago for a ridiculously low price, but I just wanted to mention that the thread title gave me an earworm that stayed with me the whole day.
A good mattress these days is hard to find
True love, the lasting kind
A good mattress these days is hard to find
So please be gentle with this mattress of mine
(sorry, please carry on with the thread)
A hard mattress is good to find.
A couple months ago, I concluded that my bed was contributing to the problems I was having with my back. The mattress was, as best I can remember, 27 years old. I took good care of it, rotating or flipping it every couple weeks. But having a broken rib a year back meant sitting up in bed for a couple months. Which meant all my weight was concentrated in a small area of the bed. That section got lumpy.
So I went down to the local bed store and checked out what they had. What I was looking for was something between super extra firm and a sheet of plywood with a thin cloth covering. Of course, they didn’t have anything that firm, but I got the firmest one they had. It doesn’t have memory foam, but I don’t want that. Except for my feet, I get hot at night, and just the term “memory foam” sounded way too hot.
All the mattresses in the store had a pillow top, so mine does too. The salesman said I would no longer be flipping it because of that. But I examined the bottom of the mattress and it looked like it had enough padding over the springs, so I flipped it anyway. Feels fine. In fact, a bit better than the other side.