I finally got a chance to see it, myself. A good film, but not a great one. Unlike, for example, Perfect Blue — also directed by Satoshi Kon and also dealing with a world where it becomes impossible to distinguish fantasy from reality — this one submerges us into weirdness too soon, making it impossible for us to tell what SHOULD have been real. For example, we never see the dream device successfully used to treat the delusional patient. nor do we even MEET the delusional patient Instead, we see one dream taken over by another dream, and one of the characters has to TELL us, "Hey, wait a minute, this is the dream of that delusional patient I treated!" Nor do you ever see any kind of relationship developing between the doctor and the fatboy.
These were my main reservations. Other than that, the images were goregeous, the action and dialogue was engaging, and you can't go wrong with Megumi Hayashibara and her sexy voice as Paprika.