You nailed it there, Sam. In previous games we kind of pushed through and did some backtracking on a set stage, but having an open world and selectable missions like in PW is the best formula.
Apparently resource crates wont respawn in these open world maps, but we can fulton vehicles and disassemble them for resources should we need them, as well as steal them from other players FOB. I like this idea as it keeps players on the field procuring things and people in order to make up for losses in a failed FOB defense, and your crew killing each other or getting sick, or dying in outer ops.
It's the game that keeps on giving, even after completing all missions, we will still be researching weapons and gear, having fun raiding FOB's and MGO3 in October, this is GOTY right here.