I listened to this book as a Brit who lives in the UK, and came to it having not previously read any of Isles’ other work. My takeaway is that if you have the time, this is absolutely a work worth engaging with, that will cause the reader to think deeply about the current state of the US and elsewhere.
Without giving away any spoilers, it felt very real given the backdrop of violent political instability in the US, particularly in the light of the Trump assassination attempt. Although of course a work of fiction, and taken to some extremes - especially at the denouement of the novel - I felt that it painted a vivid and insightful picture of the deep divides facing modern political culture (even beyond the US).
On the legacy of slavery, I felt the author did a good job of handling this sensitively and bringing out its lasting socioeconomic ramifications. I do think some of characters become overly patriarchal and too easily adopt white saviour attitudes, but to be fair to the author, for the most part he is aware of this and has other, black, characters call it out.
The main downside, as others have highlighted, is the length. At 45 hours listening time it is a considerable investment, and a decent editor could have cut considerably without losing much of what makes the book so good. Because it veers at times into the polemical (in the Aaron Sorkin mould) I think the author has been given a little too much licence. But overall this does not detract from what is a book that will really give back on the time investment put in.