If you're looking for insight into Kubrick's mind, I doubt you'll find anything that will give you an accurate assessment on that. Nelson lays out an ingenuous analysis of Kubrick's body of work giving erudite insights using Kubrick's noted influences and techniques.
I picked this up on the way to see The Shining at the TIFF lightbox in Toronto. I flipped over to the chapter on The Shining, titled "A Remembrance Of Things Forgotten" which is an interesting play of words from Chris Marker's visual essay on photographer Denise Bellon (which I saw that same week). It seems it was the right place to start the book from for me since that's where the Kubrick maze is fully exposed, literally and figuratively. There are a few things in here I hadn't picked up on and Nelson makes note of Kubrick's intrinsic knowledge of cinema's origins and how he builds upon it. Circumventing any of the familiar conspiracy theories by keeping morphology in literature and film grounds, Nelson dives in frame by frame, transposing philosophical ideals that were used to create some of the most iconic moments in film. I especially liked reading things that I had not paid attention to, and have now become crucial to my re-watching of said films.
Formula, formula, formula Bunuel! I'm a stickler for film devices and Kubrick soared above the established ones.