Have you watched the news on a semi-regular basis over the past 2 years? Have you ever read the president's tweets? And lastly, are you modestly intelligent and can make simple inferences based on what you watch, read, and listen to? If the answer to all those questions is yes, then 95% of the information in this book will either already be known to you, or you will have guessed it as much.
What of the other 1/20 bits of data found in this book that may be new? Wondered what Trump affiliated lawyer Sam Nunberg was doing prior to his bizarre, incoherent, history-making 8 interviews in one day, shattering the previous "Full Ginsberg" daily record of 4 news interviews during the Clinton-Lewinsky affair? Hint: Snorting copious lines of coke off of a female prostitutes body part, at least according to Steve Bannon.
Did I want to know that? No. Could I have guessed it from Sam Nunberg bug-eyed performance during his interviews that day? Probably. Is this really important to get to the bottom of the whole mess that is the current administration? Possibly.
The above actually accentuate the issues with the book. Like the previous book "Fire and Fury", this book's "value" to the well-informed reader is that adds much color to what *may* be going on in the background of the current administration. I write "may" because, like the previous text, it is highly suspected by many readers of both of Wolff's books that the primary (and possibly sole) source for most of this book is, in fact, Steve Bannon, who is an unreliable conveyor of information at best. In fact, you can see Wolff in the background hanging out with Bannon during the November 2018 election night events in a scene from Allison Klayman's recently released an acclaimed documentary on Bannon, "The Brink", which followed Bannon contemporaneously in the same time period as "Siege".
The portrait we get of Trump is not at all dissimilar to what is apparent from his public performance, an extremely self-centered individual, who has little patience to read his briefings or study issues, has bigoted mentalities, frustrates everyone that works for him, and has very little capacity to engage in "long term" or strategic thinking, leading to poor decision making that diminishes US economic and political standing vis-a-vis other nations.
What else is there? According to Wolff, Trump has claimed an "encounter" with Nicki Haley, to leverage a Clintononian terminology for the "act" in question. Wolff suggests this is just bluster and probably not true. Though, according to Wolff Trump has engaged in similar activity with subordinates when he was a businessman. Other less salacious notes include the way his son-in-law has come to be the "man in the wall" of US diplomacy, and how he has performed (or not performed) to the task. How Trump's habit of blaming his subordinates for all failings in his leadership provokes animus against him from his administration, Trump's habit of eating bologna, his fear of going to jail (which has recently flared up in public during his D-Day 75th anniversary travels to Europe), and other similar things.
Yet again, none of this will be a surprise to anyone who even just passively follows the news. At best, this book validates what one observes. At worst, it fills in details with tabloid rumors.
Not to say that the story Wolff has written isn't entertaining. There's much hilarity in this book, in a "The Wolf of Wall Street" kind of way. These books will make Wolf spectacularly rich one day when they're optioned and turned into a biopic dark comedy. Assuming the remainder of the Trump years doesn't end up being profoundly tragic because of errors made by the administration on the world stage.
Unless you can get this book in a severe discount (or free) one can probably hold off on it. If you're entertained by reading about a three-stooges like a team of grifters, a sort of anti-Ocean's 11 and have nothing to read, it may be a decent pickup. I'd suggest you could get 90% of the same effect by just watching Steven Colbert's "Our Cartoon President".