I have seen nearly all of Akira Kurosawa's films, so my opinion shouldn't be completely ignored. Although I am in the distinct minority, I didn't particularly like KAGEMUSHA. Yes, it was big and beautiful and had great scope but it was also emotionally sterile and bore little resemblance to Kurosawa's earlier, more famous works. The same, by the way, can be said about RAN. Both films had relatively HUGE budgets but the dialog and connectedness between the characters was lacking. As a result, I felt pretty bored when I watched both of them--especially this film.
So, if you compare these two movies with THE 7 SAMURAI or YOJIMBO, for example, they seem VERY different. These older films, though not filmed in color, had a greater sense of humanity about them--great importance was placed on the INTERRELATIONSHIPS between the characters AND the camera work was very different, with more closeups and a more intimate feel. So, while RAN and KAGEMUSHA were pretty to look at, I felt much more detached from them and cared much less about the characters. I really think the problem with these two movies, and the reason I like them less than the average Kurosawa film, was that the big budget in these later films actually HURT them, as too much emphasis was placed on effects and dialog was purely secondary.
So, in summary, I am the odd-ball that didn't love this film. You will probably disagree and might be tempted to mark my review as "not helpful", as the reviews on IMDb are generally glowing. But having seen many Japanese films, I can't help but feel there are better films out there waiting to be seen. Most any other Kurosawa film, and films by other great directors (such as THE SAMURAI TRILOGY, the films of Yasujiro Ozu) are more appealing to me. I think the popularity of this film is in part due to its having been seen in theaters by more Westerners than any other of Kurosawa's films--SEEK OUT HIS EARLIER AND MID-CAREER FILMS--they are better and far more emotionally involving.