The sound design took this film to another level
I noticed instantly what Fincher did with the sound -- making it sound like an old film with "thin voices". This totally works, and it makes the film unusual and singular simultaneously. It gives the film weight, and an advantage over other retro films.
The film was really good. Only problem was the discredited notion that Mankiewicz wrote Citizen Kane alone. Orson Welles had a big hand in shaping the screenplay for the screen. For example the famous breakfast scene in Citizen Kane was Orson's invention.