I think it's important to firstly note that this anime is heavily influenced by Japan's history.
It is a re-telling of what Japan went through in the final years of the Edo period, when the Samurai, Ronins, Citizens, and Military forces from Japan and foreign countries, fought for control of the country. The interesting battles and real-life tales of betrayal and backstabbing, are retold with a hint of the supernatural element, which although seemingly far fetched, does hold more than a hint of realism. The story is fascinating, but if the viewer is not into the history genre and does not care about sitting through, what may at times seem like a history or Asian culture class, then this series is definitely not for them.
I enjoyed this tale immensely, as it was good to see the behind the scene drama of such an important era in world history. Some of the events are fictional, injected into the series so as to make it more "watchable" and a few of the characters never existed in real life, but it does make things fascinating.
The Supernatural factor, which focuses on the protagonist's journey to destroy an object that is too powerful to remain intact among humans, can be used as an element to show what happens in real life when man becomes consumed with power and greed, and their drive to do the "right then" soon gives way to the very thing they sought to fight against. Though the powerful object did not truly exist, the story does well to incorporate into history.
The Art for the series is good. It suits the story and its time-line perfectly, and is solid for all 26 episodes. The only problem I had, which really boils down to my preference, is that the art does have a smoky-like appearance at times, as if it is being viewed through a very very thin film of mist. I can understand why the method was used, as it does relate to certain scenes in the story, but since I like to view things nice and sharp it didn't win me over completely.
I am going to go out on a limb here and say that the sound is good, despite there being only a few scores, which were all used repetitively. But the thing is, they suited the story perfectly and since it's obvious that the creators did not want anything drastic and over the topic, it was right on the mark.
I'm tempted to say that the characters are Very Good, but I think "Good" is more accurate.
The lead protagonist, Akizuki, has quite a somewhat stiff and at times unreadable attitude, which suits his role perfectly. It may be viewed by some as "boring" but when really get into the story, you can tell why it's the best design for him.
Ibaragi Sōtetsu's character is one to look out for, although I don't need to tell anyone that because as soon as he is spotted, he will command your attention. I think it's very common for a character to be present whose true motives are unknown to the other characters, but very obvious to the viewer, but in Sotetsu's case he will keep you guessing about his real intentions until the very end. His character design is practically flawless.
Those two aside, even though a majority of the character designs aren't particularly intricate, someone will pop up every now and then that's quite interesting to watch.
So like I said, I enjoyed the story enough, even though it may not be extremely outstanding or addictive. I also can understand how the consistent 'history lesson breakdown' may easily be confusing and annoying to some. If you're interested about Japan's past, and a realistic view of Ronins and Samurai, you should really give this series a shot.