All of the above.

Let's also not overlook the first face/voice we see in the Trilogy - Salvatore Corsitto as Bonasera. He starts things off with a powerful recitation of his daughter's tragedy and then wonderfully crumbles as Vito makes him do something he really didn't want to do - pledge fealty to the Don.

To me, for all of the criticisms of GFIII, the real difference between that and the first two films is the acting. There are plenty of loose ends and inconsistencies in GFII (that we're still debating today) but we still buy into the story because the acting is so perfect.

With poor performances small (Hamilton) and large (Wallach, Sofia), we don't extend the same grace to III.