As a scholarly study of the subject this book deserves high praise. As a 'good read', in English translation at least, it falls short. Though quite possibly definitive for the time of its composition, the detail of the very many plots and plotters is often overwhelming. There are literally hundreds of actors to keep track of.
This is not a book about assassination attempts on Hitler, of which there were, to our knowledge, scores. Some are mentioned, but only a few are focused on. Rather, Hoffman is primarily concerned with the resistance of the prominent, those being in most cases government and military officials. Receiving the most attention is the Valkyrie event of 1944 which concludes the book.
Most disturbing to me were the accounts of German torture techniques, reminiscent of the 'advanced interrogations' conducted by the Bush administration. Most encouraging to me was learning how very many senior German officials opposed the Nazis at the risk of their own necks.