This is Truth in Television - Heydrich really did have the nickname "The Man with the Iron Heart"—and that nickname was given to him by Adolf Hitler. He was directly responsible for nearly a quarter of Jewish deaths during the Holocaust. And he did all that at the beginning of the war, as he was assassinated by British intelligence in 1942 in our timeline. Definitely one of history's worst monsters.
Follow the Leader: The first few editions of the book had covers with a rising sun and a swastika side-by-side, sometimes dividing a map of the United States in half. Simple, direct, and to the point, right? But in the late 80s, after the release of the Cult Classic PKD adaptation Blade Runner, all of a sudden we get this◊. Although the book mentions that Nazi technology in rocketry has advanced, nothing in the book even remotely suggests the San Fransisco of this alternate universe is the kind of cyberpunk metropolis Blade Runner popularized. In fact, when Tagomi crosses over to our world, it's suggested the San Fran of the book is even less industrialized.
Hilarious in Hindsight: The way the Japanese fawn over the tritest American kitsch in the book is funnier now, after the rise of anime and manga fandom in the United States, some members of which do the exact same thing to Japanese culture.
Nausea Fuel: The Nazi doctors inventing new uses for dead bodies, such as using the joint of the big toe as a mechanism for a lighter.