As powerful as an actor he is, you tend to forget he is not a big guy.
The first time I ever saw Pacino in person was on Broadway in 1984, in "American Buffalo." I was SHOCKED at how diminutive he actually is.
By chance, I happened to be at Christie's auction house in NYC for an art exhibit, and I ducked into an auction they were holding for movie and theatrical artifacts. One of them was one of Pacino's suits from GFIII. It was so small, I kept wondering if he wore it in the film--or to his First Communion.