Here is a chart comparing most common insulators
As you can see closed-cell (Which I use and recommend)spray foam is by far your best insulator and it is far superior over other insulators beneficial wise. R value is close to r7!
Closed cell Polyurethane is superior!
As you can see closed cell polyurethane foam outdoes the competition in almost every category. I can spray open or closed but in our climate closed cell insulation is needed. The only use for open cell in our climate is for sound barrier on interior walls.