What I want to know is whether this is a dated text, if there are factual inaccuracies or misconceptions about the series of events. I don't want to repeat what I've learned from the book only to learn that the conception of events changed forty years ago.
I will leave historical judgment to my betters, but should point out that Shirer lived in Germany during the war, and even though there's relatively little personal narrative, the whole thing has a pungent aura of first-person observation. I am glad to have read it.
His hatred of Goering is distracting, though. Shirer had to point out his corpulence with petty and depressing regularity.
It is still a foundational work, but WWII scholarship has evolved significantly since then. It is only outdated in the sense that most WWII historians today tackle the big three concepts of "Race, Gender, and Class" rather than bare bones chronologies.
I wouldn't say it was dated it is missing some things such as no mention of enigma since it was only declassified after he wrote the book in 1974. However since all major players were still alive he could interview and ask them what they meant in their diaries. So I would say nothing in the book is wrong per se just that not all the information was available to Shirer. It is an excellent read though.
A previous submission probably of interest to you: