I don't have this case specifically, but I do have some similar cases with pick n pluck foam for microphones and stuff. Just from my experience, and maybe the one you're looking at is different, but this pre-cut foam tends to be a little bit softer (weaker?) than the types that are custom cut from solid blocks of foam. Maybe because of all the little cuts throughout the foam, I don't know.
It might not make any difference with a Phantom, as they aren't that heavy anyway. Just thought it might help you to know. By the way I have several Pelican cases, some of them I have had for close to 10 years now, and they are absolutely rock solid.