DC, I must agree with you. I actually have great affection for GF3, with the exception of Sofia's acting. I find that there are some very compelling scenes. However, you can't compare it with the majesty that are the first two films.
What I thought was interesting was the "Making of Godfather III" that HBO did when the movie was first released. It was very interesting to hear FFC speak about Michael as if he were a living and breathing person. He was talking about his quest for redemption, and what motivated him to do so. It was fascinating, almost as if he was Dr. Frankenstein talking about his creation.