Here is my advice: Watch the movie first, before you are reading the screenplay. Some of the scenes don´t work that well when you read them and you should definitely experience the story through its gorgeous cinematography and the great acting of the three (well, okay four) actors.
But I have to say that I enjoyed reading the screenplay. It follows the movie pretty closely, but there are some additional scenes and stage directions that give you some new insights to the story. I definitely have to watch the movie again just to pay closer attention to certain things like Ava´s demeanour in certain situations and pretty much every single scene with Kyoko in it.