Fest's biography of Hitler has been praised for its literary qualities and described as a milestone in the history of the Federal Republic of Germany.Brendan Simms: Hitler. Eine globale Biographie. Deutsche Verlags-Anstalt, München 2019 p. 13 Others have criticised it as weakly researched and too dependent on dubious testimony by Albert Speer.Magnus Brechtken: Albert Speer. Eine deutsche Karriere. Siedler Verlag, München 2017, , p. 58, 393 ff. Fest has been accused of helping Speer create legends about his role during the war.Christian Gampert: Albert Speer und seine Helfer Geschichtsfälschung für die Mär vom unpolitischen Technokraten. In: Deutschlandfunk, gesendet 30. April 2017.Rudolf Neumaier: Die Mär vom "guten Nazi" Albert Speer. in: Süddeutsche Zeitung, online 7. Mai 2017. , a retired army German officer and military historian, has described Fest's works as an example of a class of publications that influenced German public opinion that should in retrospect be considered very problematic (in a text about German anti-Nazi resistance).20. Juli 1944. Neue Forschungen zum Widerstand gegen Hitler. Im Auftrag des ZMBw hrsg. von Jörg Hillmann und Peter Lieb,
