As for the art, it stayed the same as it was before and it also adds to the mood and the character's attitudes.
The sound went well with what was going on at the time, not much to say about the sound other that it was well-fitting most of the time.
The characters have surely changed throughout the series, most of them anyway. The character's (especially Ciel) change quite a bit. For the characters that didn't change, they still have very lively or unique characteristics.
For the most part the series was enjoyable, as I refuse to use spoilers... I will only say I thought the ending was well done and Claude was an excellent villain, as he made Sebastian feel less than perfect.
Therefore, I enjoyed the anime, yet it is not my favorite. I do recommend it if you are into this type of genre.
