I really liked the idea of this book, especially the idea of how the silverbars work. I thoroughly enjoyed the first half, I am not so sure how I feel about the second half, but I was definitely engaged and wanted to know what would happen. 
A word about the audiobook: the narrators did a good job, I liked the different narrator for the footnotes. However especially in the first half of it the audio mix was horrible, you can clearly tell when a sentence has been edited. Sometimes I thought that there were like 4 people saying just one sentence, which took me completely out of the story. Fortunately this got better in the second half, but it was surprising to hear in a professional production.