This is absolutely a brilliant interpretation of the 1100 page book by James Clavell. Of course some details are left out, but I reckon only one time in the movie are you in doubt of whats going on (I am referring to the episode where Toranaga tries to escape the Ishido castle).
The movie is very close to the book, which for me, was a positive experience.
The story is well told and good acting is shown through the whole movie. The nature of the movie is, that when having watched an episode it is very hard not to see the following and the following and so on.
Are you into samurai stuff this is clearly a cool movie - note however, that there are not many battle scenes.