I've been an avid reader of Philip K. Dick for 40 years and have seen several film adaptations of his work. In terms of storytelling, none of them come close to this one. (Blade Runner is a classic rendering of Dickian atmosphere, but is only loosely related to the story it is purportedly based on.) Linklater follows the original novel closely in incident and dialogue, with only minor and judicious changes. The rotoscoping technique works perfectly and makes the most of excellent acting by the whole cast; the result effectively blurs the line between reality and hallucination. And the film leaves us with plenty to ponder, just as Dick's prophetic novel does -- some of it intensely personal (Do you really know who your friends are? Do they know who you are?) and some of it covertly political (the terrorist "war on drugs" bleeding into the paranoid "war on terror"). And on top of that, much of this film is hilarious. Definitely worth watching several times.