First of all, this can be a misleading book. It was originally published as Chariots for Apollo: The making of the Lunar Module in 1985, then was reissued as "Chariots for Apollo: "The Untold Story Behind the Race to the Moon" in 1999. Well, no, it's about the history of the lunar module, and it was hardly untold since it was published 14 years earlier. (There is an unrelated book Chariots for Apollo: The NASA History of Manned Lunar Spacecraft to 1969 by Courtney G. Brooks that came out in 2009).
It's one of the few disappointing books I've read about the space program. Pellegrino has an annoyingly overused tendency to comment on text "in" the text - something I remember from his book on the Titanic, and it's distracting and often confusing, since you can't always follow his train of thought. Second, in a couple of places he just gave up trying to write and included transcripts of interviews he had with participants - a real WTF moment for me.
I have a pretty good understanding of the story of the challenges the engineers faced building the lunar module, and this doesn't tell it. It skips over development to the management of the lunar module at KSC, and while that's an interesting story and he has lots of good anecdotes, it's just not a well told story. I've read (and seen) better accounts of the LM story, as well as the KSC story. This is way too idiosyncratic a book - you never forget that it's an author talking about a subject.