I had wondered if a detailed working out of the doctrine of the Will to Power would be published. Despite 'decisive refutations' of the doctrine as a product of the mature Nietzsche (Montinari, Clark, Leiter,) and the (to my mind unconvincing) attempts to use the doctrine (Schrift - argument too weak, Deleuze - argument lacks detail), Richardson bravely attempts to see where the doctrine might lead us if we take it to be central to Nietzsche's work.
Some of the reading is unpleasant, since the attempts to cleave the Will to Power from some of Nietzsche's more notorious passages, accusations of anti-semitism, sexism, etc, would be seen to have less weight than writers such as Kaufmann would have it. However, Richardson's work is of immense value to Nietzsche scholarship.
The question of whether the will to power is a central thesis of the mature Nietzsche, I suspect, must be answered negatively. But that by no means entails that we should only consider the mature works, nor refuse to consider the substantial fertility in the idea of the Will to Power. (Speaking for myself, I prefer the Tractatus to the Investigations, Word and Object to The Roots of Reference).
A fantastic book.