Most commentary on this film has focused on Carey's portrayal of Kaufman. Such total immerson is always fascinating as is the public reaction. If you do it in a dramatic film (As in "Raging Bull" or "Shine") you can win an Oscar. But you do not need the Academy to tell you this is not a dramatic film. However, I really believe the best way of considering this film is to focus on the director more than the star.
The best parts of this film are at the beginning and the end. The opening sequence is simple Kaufmanesque, which, in retrospect, is a brilliant ploy. It sets the mood perfectly. At the end, with Kaufman's trip to the Philippines, is the final punchline to his life. Of course I do not want to give it away, but if you consider it from the perspective of Kaufman as the comedian who always cried "wolf," you have to appreciate the supreme irony of the moment which sums up Kaufman's life, both symbolically and literally (Note. Even though the cast credits are not at the end of the film, please make a point of staying around until the end of the credits. It is not a big joke, it is simply a pleasant surprise).
I watched this film with my kids who know nothing about Andy Kaufman. They knew who Carol Kane was from "The Princess Bride" and whathizface from all those "Back to the Future Movies." What was interesting to me was that they bit on the entire movie. No matter how many times Andy cried wolf, they fell for it. At the end they were convinced he was not really dead. Regarding the deleted scenes, I remember seeing Zmuda tear apart Kaufman's act on cable. I wish it had been kept in the film, because its one of his better triple twists.
This is not a great film, but it is a very good film, especially given its subject matter. If you do not like Kaufman, or are not willing to at least give him a shot, you probably will not like the movie. Nobody thinks Kaufman walked a fine line. He was over it. If that bothers you, then you will not like this movie. You have to take him at face value (and, yes, I appreciate the irony of that comment).