I wouldn't say Cloud is anything, as for much of the game you actually get to choose what he says and does. FFVII introduced actual role playing elements in the series by allowing you to determine the way the protagonist interacts with the rest of the cast, all of this resulting in an actual event that can change, the Gold Saucer date. Of course some of these choice-sets are simply variations on being a dick or a hero, but for the most part you got to determine who Cloud was, especially on the first disc.

Like others have said, Cloud in AC felt really out of place because he was going through the motions of things you felt were already resolved in the game. I guess the GeoStigma thing threw it off balance, but overall I was satisfied with Advent Children for what it intended to do.