Though Maser's treatment of Hitler is not as readable, fluid or as definitive as American John Toland's 1977 biography, this is the second-best biography written about Hitler. Though this concentrates solely on Hitler's last days, it is lifted directly from Maser's masterful Hitler biography.
Maser's historical credibility was compromised in 1977 by his announcement that he had discovered Hitler's "son," Jean Lorret, the result, supposedly, of Hitler's relationship with a Belgian peasant girl in World War I. The original German-language edition of this book carries that story, with photos of Hitler's alleged paramour.
This book is not good for novices, and it would help if there was a backlog of knowledge about Hitler prior to tackling Maser's prose. But for those who are well-versed in Hitler, this is an excellent book.