I have a wooden bed with slats which I nailed down soon after I bought it ~40 years ago as they slid about. My mattress is over 20 years old, & is thin rubber foam! I thought it was 6" deep, but it's about 4, & I have a very thin mattress topper over it. I sleep well even tho I have chronic back pain.

Last year I was pondering upon a bamboo mattress topper but haven't done anything yet.

A friend suggested a memory foam topper, but I checked out Pros and Cons of Different Types of Mattress Toppers & cons won out "Can be hot & Can make it difficult to turn over or shift in bed"

sandra