This is not a quick book to read (I started in January and finished in May - though I read more intensively at the end). You have to learn to slow down and sometimes persevere (I am not a native German speaker, but can read German fluently: however, the vocabulary here is often unusual and does not appear in fairly large dictionaries). The story becomes more interesting towards the end.
What I loved about this book: the descriptive passages were often very beautiful and intense. I liked the romanticism and intense sentiment, though that may not be for everyone. I enjoyed the mystery and intrigue.
I was less thrilled by the certain motifs which kept recurring: the sunsets and nightingales became a bit tiresome and blindness/sexual predators, Doppelgänger etc were somewhat overused. I also found it a little disappointing that it seemed as if the novel was all about how to become great (a titan) but I felt that the protagonist's personal development became a bit overshadowed by the events he had to react to, so he seemed not to have so much agency.
All in all, however, I would recommend it - to people who like a slow, poetic read with romanticism, sentimentality and intrigue.