I know the book by heart, and this mini-series is incredibly close, it's practically word-for-word; they've omitted several small non-essential scenes, made a couple beautiful, logical additions, and otherwise changed perhaps a dozen words or so.
Almost all the scenes are exactly as I had always imagined them; casting is incredible (except for the awful, miserable Pilate - regret of a small, cowardly man is never as tragic as that of a strong man). Joshua is beyond words - seeing... Him gives you shivers, never before has there been such a portrayal of Jesus in cinema. Woland is breathtaking, down to the voice. The final scene of Woland contemplating the city from above is like a Goya painting.