As a director he was not that interested in Vader.
A director should be in a position where he is only directing. On the sets, he is only looking at the performances, thinking 'How I am going to shoot this?'
I look at actors very closely. It's not an accident when the actors excel.
Some directors are interested in acting, and others are only interested in cranes and moving the camera.
As far as writing and directing, I'm very focused on the thriller genre.
It can be insulting to an actor when the director comes out, and they have no notes on the performance, and all they care about is that the camera has to do this one technical thing.
The core to what makes Fincher really interesting - all the technique and all that, that is not in the center even if it's a big big part - what is in the center is the characters, and he really is interested in that.
You are treated like a cog in a machine. The director might be obsessing so much with the stunts that he doesn't notice your performance, and the producer may just be an insane money man, but I have no snobbery about the movies.