I think it's a toss up on the Depron Vs. "Ultrafoam"

Ultrafoam is just FFF without the holes and waves.... It takes a little more abuse, but is harder to repair... it is lighter (by a mouse hair) , but the film will "craze" under flexing...

I prefer Depron simply because it laser cuts better than any other foam.... but if you aren't using that advanced technology for cutting the kits....