Like probably most, I read the book after seeing the author's little skits on social media, which were amazing. 
I liked the concept and the mixture of different levels and stories. Caroline's story captured me as much as Rosy and Leo's. And Caroline's fight with the protagonists was really funny. My writing experiences don't go beyond early 2000's fanfiction, but I know that feeling ;)
For some reason, it took me quite a while to get into it but I cannot point out, what was not working as well in the beginning. Somehow the style of the story-story felt not yet great but quite flat. But whether it improved or I got used to it, I don't know. I have trouble to recognize that (English is not my first language.)
The other thing that troubled me and my enjoyment of the book where the problematic views of the author (calling TERF a slur, etc.) that I only discovered when I had started the book. (fortunately, I had it from the library) I'm honest enough to consider that it made me like the book less, because I'm really biased when it comes to trans people and rights, because one of my fav people is trans.