Knights of Sidonia is one of the first titles I encountered as a recommendation when I first got into manga. Since then I 've been curious to check it out but it mostly stayed as a staple in my Plan to Read until I randomly decided to give it a chance not knowing what else to read. Having read BLAME! (which I didn't really enjoy) I expected another compilation of cool art and a loose story and well... I was wrong.
What I liked:

1. As someone who has studied architecture, Nihei does an amazing job visualizing his fictional worlds. The environment always looks authentic and provides for many great panels.

What I didn't like:

1. Unlike the locations in the story, the character designs in Nihei's works are simply unimpressive. This is especially problematic when the story has as large a cast as in Knights of Sidonia. Most designs are unimaginative and feel deprived of any life to such extent, that the most interesting character visually is just a bear (kinda).
2. Having striking detailed designs is not always a necessity, however. What really matters is the characters themselves. Well Nihei fails to deliver yet again. The entire cast feels extremely bland to the point that I can't say anything about any of the characters' personalities. All the slice of life moments were like watching robots exchanging prerecorded sounds. Due to this being the case, my involvement with the story was minimal which leads to the last point.
3. The story of Knights of Sidonia was as basic as it could get.
   Spoiler, click to view

   It followed the same formula of enemy appears ---> good guys fight enemy ---> back to normal for the ENTIRE time. It became repetitive so fast especially due to the previous point and helped frustrate me to no end.
   To add insult to injury, the dialogue is 80% random terminology which after a while became indifferent to me as I did not care what happened anyway. There is also the fact that Nihei never forgot to add a cheap fanservice moment at least once a volume as if he was trying to make the readers not leave before the story gets to its peak.
4. Finally the ending was dumb.
   Spoiler, click to view

   Having our main character end up with his dream girl regardless of any logic felt purely forced. Not to mention how the great revelation that he is a clone was used as a brief moment of shock and had no purpose. The final arc in general was not much different from the previous with stakes being as low as possible.

Overall I can say I totally wasted my time on a manga I will soon forget. I think Tsutomu Nihei should just do art exhibitions and not make any more miserable attempts at storytelling. So unless you are a major fan of his, don't read this series. It is not good.