I have tried latex, latex over pocket coils, all foam, foam over pocket coils, foam over Bonnell springs.
Can't stand pocket coils, feel like I'm sinking and get a lower back ache.
Cloud nine/Sloom, very comfortable, perfect for 1 person, add another and it's unbearably hot.
Natural latex, too hard, couldn't get comfortable.
I'm just going to go back to a trusty Bonnell coil now. They're easy to move on, cool, and last long. Sealy's system seems to be the best, old bed is one and I think it's a continuous coil unit.