I thought this was absolutely brilliant. In my opinion, more unfounded myths surround Duchamp than any other artist; this book is a great corrective. Many theorists and commentators unfairly use Duchamp to justify their opinions. Reading this book exposes the truth. Raed this to find out what Duchamp really thought and believed, not what lazy critics with only a cursory knowledge of the man, say he believed and thought.
Further, not only is this book illuminating about Duchamp, it is also illuminating about the entire birth of 'modern art' in Paris in the first half of the 20th century, with lots of detail on a wide range of different artists and movements, including Picasso, Braque, Matisse, the futurist movement, the surrealist movement and so on.
Further, Tomkins is an entertaining writer, and this book, in my opinion, is exactly the right length and size (as opposed to Jon Richarson's 3-volume Picasso, and Hillary Spurling's 2-volume Matisse, which are perhaps a tad over-long for many people).
To conclude, yes I am a big fan of this book, and I cannot believe it is not more widely available.