I have tried loads of toppers, since the RIB is basically concrete.
Slept on it once bare. Never again.
Then used 10cm vango inflatable. Pretty comfortable but lost air and was a nightmare to roll up. Decided to move on.
Then tried 2.5cm “compact” Duvalay toppers. Wife was comfortable. I was not.
Then tried 5cm “gold” Duvalay topper. It’s fine, but not amazing.
I’m fairly boney, and I’ve learned that I get a sore hip and back if the bed isn’t right.
I’m going to keep tinkering.