Hi
Hi
Nice to hear from you.
Most people use 4″ foam. 5″ foam is more comfy, though.
I think the curved bed slats do need some room to move. My home bed has slats that have rubber cups that the slats fit into, and allow some movement.
Zoom into the pics on this page to see the black rubber cups
http://www.ikea.com/gb/en/catalog/products/20278718/
Cheers
Darren