Foucaults thinking is a mess. Foucault would be the first to acknowledge this. This book however falls into the trap of unifying his thinking into a grand project when in fact Foucault was always shifting interests and changing the course of his thinking. The biographical reseach also gets thinner towards the end of this book. And the postscript that attempt to absolve Foucault from having knowingly infected numerous sex partners with AIDS is just ridiculous.
This book is perfect if you want to focus on the late Foucault, who is a surprise if you know nothing about the historical and biographical developement of his thougth. It will give you a big hint if you are disoriented within the bunch of colors in his estense work. That's at least what it did for me. However, the book may give somebody the idea that only the late Foucault deserves a reading, and that one is not loosing something skipping "The order of things", or "Discipline & Punishment", two real classics of our time. The audacious ideas arising in these two books deserve attention because of their actuality and originality, and because of the sour critic they implicate for existing philosophical schools. The rare anecdotes (i.e.: the conversations with Habermas) may discourage one to think seriously of the main themes of the early Foucault, and that's why I'd recommend a previous reading of Foucault's early works from the beggining until the first volume of his "History of sexuality". Miller's book will make things more clear without taking out all the "Passion" that someone like Foucault may arise.