The exchange early in the movie Amadeus seemed poignant. The elder Salieri was clearly gobsmacked at Mozart's command of music. He paid Mozart some compliment, to which Mozart's character replies: when you have it crammed down your throat since age 3, its not hard.
I haven't seen the movie on Vivian Maier, but I saw Amadeus and, as entertaining as it may be, it has nothing to do with Mozart and Salieri. They were both perfectly normal persons. Mozart is depicted as some mad clown and Salieri as a jealous maniac. Salieri was one of the founders of Vienna conservatory of Music. He wrote for Vienna, Paris, Milan and had a huge fame, greater than Mozart's.
Since 1790, when he was only 40, he withdrew from all international engagement and only retained his post as Court Composer in Vienna because he wanted to dedicate himself to teaching. He was famous as teacher of singing and vocal composition. He was the teacher of Beethoven, Schubert, Liszt, Meyerbeer, Hummel and Suessmayr. As you can see, this is not the kind of person who was jealus of somebody else's success! Beethoven dedicated to him his three sonatas Op. 12. He was the darling of Viennese, or European, composers.
The portrait made of him in the film Amadeus makes of him the most defamed composer in history. There should be some respect for the memory of people!
Emperor Joseph (or Josef) II certainly would have never said to Mozart, or to any composer, that there were "too many notes" in his composition, and other such imbecilities, being not an imbecile and being an amateur composer himself.
Don't take that film, (or any Hollywood film), as a reliable biography!