I watched this a few months ago and I really quite enjoyed it. Some of the themes in it are probably uncomfortable for a lot of people and so I understand why a lot of people would dislike it. However I feel the show's strong point is making you consider your own beliefs on controversial themes, the Sora arc definitely doesn't come as a shock after watching the first few episodes. The topic of incest is really controversial because no one can clearly state on a case by case incident what the right answer is, because of this it's really interesting to see how the other characters react to this and how the twins react to it themselves.
Obviously the incest section is only the final part of the show and the rest of the anime has some really good character and well-placed drama so if you wished you could just skip the Sora arc and still enjoy the show.
Overall I enjoyed it because it gives you a chance to see things through a different perspective and how different things can look in different circumstances. Overall I give the show a strong 7/10
