I ADORE THIS BOOK!
German is my third language, but I decided to listen to the original (German) version and had no problem understanding it.
The language was a bit easier to understand because it is very youthful, but it also helped me broaden my German vocabulary thanks to the amount of slang used.
The narrators voices fit their roles so well I actually felt like they were a part of the story.
It is a very strong story, written in a captivating way, that makes you want to never stop reading it. The atmosphere sucked me in right away and I couldn't help but get emotional many, many times.
I even cried at the end, because of being sad the book ended already.