In acting department, the movie fared well overall but for some misfits. Amitabh's charisma worked more than his acting skills. I feel he was not the best man for the role regarding the requirements of personality traits and appearance. If Francis Coppola were to direct the movie, his first choice would have been someone like Om Puri, Naseer or Pankaj Kapoor. Ramu's prime consideration was "bankability" and crowd pulling power when he signed Amitabh for the role. Katrina Kaif too was a poor choice regarding the significance of the character played by her in the story. She just served as an eye candy. Since one cant help comparisons with the original Godfather in wake of Ramu's own admittal, Katrina's performance would be judged agaisnt that of Diane Keaton who played Kay Adams. The other characters were more or less up to the mark.
Ramu also tends to depend too much on background score (may be "bhoot" hangover). It becomes irritating at times.