Well, unlike the 1/48, the hands of the Zero don't "flip" back into the forearm but recess slightly. The size of the fist is even moreso constrained by the size of the forearm, if you don't get it right, you can't transform it...cause the backpack won't be able to fold. With a 1/48, you can take advantage of the huge length space of the forearm to fit the hand in.
Haterist, I wouldn't be so quick to buy, the MG hands make a good base for a new hand design, but remember that there is no wrist articulation.