I have to say that if you like the novel, you need to see a Russian version year (1981) of four part TV series of " The Mystery of Edwin Drood". The movie is great and explores in depth Dickens' characters. The cast of actor cannot be better! The music composed by the Russian Composer, Eduard Artemiev is absolutely enchanting. To watch the sample episode and listen to Mr. Artemiev music , please go here http://www.youtube.com/watch?v=WG5N7J9kJbw
I am sorry the movie is on Russian language. However, you will be very surprised how well it is made.
If you would like to see a full version of four parts of the movie, please click here, for the part one http://www.youtube.com/watch?v=xLW_3ESsZIg
As for this BBC production, I find it somewhat hard to watch. The entire story seems to be very compressed for the time allotted. The cast of actors are mediocre, except for Matthew Rhys. Perhaps, I am coming from a standpoint of someone who has a comparison of the two different productions.