tl;dr: A manga with a plot that starts getting overtly messy once it starts coming together and lacks good character/relationship development, but looks really really good. 

This manga's plot has good concepts, though ones that aren't all that original, and was pretty solidly for most of it when it was focused more on smaller episodes in dealing with individual cheaters with only hints at what is going on in terms of the larger plot. However, as it got closer to the end and the overarching plot started coming more and more into focus, it started getting really convoluted with too much happening in too short a time with random twists and the introduction of a good amount of plot holes. The ending was still decent enough otherwise, it just felt really messy. A bigger problem was that while the characters had solid enough set ups and concepts, the character development was weak and the relationship development was even weaker. I was waiting and hoping the entire time for it to go somewhere, anywhere, but in the end nothing ever really materialized, which is a shame because it really felt like it needed something, wherein anything, even something weak, would be better than nothing.  What makes this worth reading though, is primarily the art. The combat isn't all that deep and rarely has much strategy to it, but it looks really cool. And the character designs were great, and how they were portrayed and just the general style and focus was really great, especially with the covers and color pages. That alone makes it well worth a read. 

Also, it was weird in that it took characters from Eden no Ouri, another work by the author, and just threw them in random positions, often as Easter eggs, but a couple of major roles as well. I didn't really like that or hate it, but did find it kind of strange.