Would a foam or coil mattress work better with a crib wedge or book incline?

[helaina]

We plan on using a crib wedge and possibly a book to incline our baby's mattress. Which type of mattress would incline better with one of these things under it, foam or coil?

[Rikkele]

They would probably do equally well. The foam mattresses are very firm, not at all soft. I have the foam Classica I. I will say that the foam mattresses are definitely much lighter than the coil if that is important.