Let me start off by saying that this is my first review on MAL and I hope people find it helpful!
But any way, this show I feel had so much more potential. I personally enjoyed it quite a bit, but there were some areas where it felt a bit lacking. The art was beautiful and very colorful, and the characters were great, even if a few of them could have used more development. But the story was so...hard...to follow. It was very complicated and half the time I didn't even know what was going on, but regardless, I felt the action somewhat made up for it. And also, one of the big problems was that it took them 3 WHOLE MONTHS to air the last episode. By the time I saw the last episode, felt like all the tension from the rest of the series and couldn't really get myself completely back into the story. This could have been an 8 or maybe even 9 overall for me if that last episode didn't air so late.
If you are thinking about watching this show, I'd say give it at least 4-6 episodes, and if you realize it's not your thing by then, just stop watching. It seems like the kind of show that only people who have a taste for that kind of show can enjoy.
I hope this was helpful!