I'm generally not into dystopian sci-fi movies because it's a bit too depressing for me. I only watched this because of Ryan Gosling and think that the film is really well made. Among others, I liked the plot, twists, and the thought-provoking vicarious experiences it provides.
The movie makes you question the surreal path that the artificial intelligence (AI) can end up taking. The ability of the AI to fool you and it's replicants is just beyond comprehension at this point and the movie tries its best to deliver the message. In a normal setting, how on god's green earth will you be able to differentiate between a real human and a replicant in the future? How do you know for sure that one of the AI replicants isn't living a life just like us, right now? How skewed would the future be if an average person is an AI replicant? How would it feel to think that you're real, only to realize that you're not. Depressing, right? I find it so.