Digging up my own thread here, but I want to post that I like the way that diecast metal is being used in the restarted Movie Masterpiece line. Since quite a few movieverse designs feature what looks like bare, unpainted metal, the use of metal adds to the appearance of the robots - Barricade is the only one who doesn't have unpainted metal.

It's also good to see that thought went into the placement of the metal - it's not there just for the sake of having it. MPM-3 Bumblebee and Barricade have it in their torsos, in parts that fold over and collapse during transformation, and all of the robots have it in their feet, which helps to keep the mass lower down in the body to counteract any top-heaviness. MPM-3 Bumblebee, Optimus, and Ironhide also have unpainted metal on their shins, again making the bottom of the figure heavier as well as adding to the appearance of the legs.