I quite enjoyed this series. For anyone that knows me, I am usually very brutal in Reviewing anime and very specific when I praise an anime. This one rightfully deserves praise.
The story somewhat reminds me of .hack//SIGN because it can get confusing if you don't pay close attention and if you don't do your research. The plot in the beginning is very basic... that goes through the first couple of episodes... then you arrive to a rival: Rider. From then on, the plot gets more and more interesting, and it makes it so that you want to keep on watching. I know I was hitting myself near the last couple of certain people... I will not go on much more about that because then it would ruin the ending... speaking of which... the ending reminded me of Chrno Crusade to a point. The ending that is sort of foreshadowed does come to pass. I'm not sure if I liked or disliked the ending at this point in time. What I do recommend is re-watch the anime from beginning to end after you've gone on Wikipedia to learn more about the characters. It makes a lot of things much clearer.
I liked the art and the character design very much. Some of the fighting scenes, however, did not apease me very much (Archer vs. Beserker for example). Besides some of the fighting scenes, it was pretty enjoyable... and I wish the artists would have stayed with one eye style per character...
The sound quality was very good. It also pleased me that the English (Dubbed) version did not change any of the background music. I enjoyed the Opennings very much, especially the second one. I did not like the first or last endings. However, I did enjoy the end song of the episode Archer vs. Beserker.
Character: Perfect 10
I really enjoyed the Character Development and the characters overall. They acted like real people, and they had those human quirks that you see in real people. Even though some characters are overexaggerated, Taiga for example, they make the anime more interesting. I especially enjoyed how some of the characters actually grew... if anyone knows what I mean. I see no overshowing flaws in the characters.
Enjoyment: Perfect 10
I truly enjoyed this anime. It was suspenceful with a lot of action while at times is was light and comical. I am in the process of re-watching the later episodes so I understand everything clearly, but I have no problem in doing so.
There are few flaws that I saw, and I definitely recommend this anime to anyone who is willing to watch it.