I have watched this movies shortly after it was released and I really loved it ! This post made me want to watch it again ! It is a really disturbing film, but disturbing in a good sens : it makes you question stuffs such as humanity, your mind, yourself, your freedom of choice. It is a simple movie with a simple plot but it focuses on the subject (AI) very deeply, giving a lot of food for thought.
In a way it is similar to a black mirror episode.
I totally agree with you : See this film if you have not done so already.