West summarises and renders accessible a massive area of thought, though as with any introduction to such a broad range of difficult ideas and their proponents, some concessions are invariably made. Perhaps being more comfortable in political theory, he more readily sinks his teeth into the political inclinations of the Frankfurt School and the so-called 'Postmodernists', giving a more thorough (if no less introductory) explication than he does of the density of Hegel or Heidegger. One positive that comes with the more politically focused second half of the book though is the improved narrative flow.
His biases begin to show through when it comes to the socio-political aspects of certain thinkers, in how bluntly he questions the legitimacy of some (Agamben), while sticking up for others (Habermas), after offering the mandatory critical gaze. To be fair, compared to the bluntness with which Bertrand Russell dealt with his subjects, this does not seem so much of a problem.
The absence of Deleuze, however, is inexcusable. He is a ghostly figure, who is mentioned only in passing (on three occasions), seemingly to tick his name off the list, without giving any information on him other than the fact that he was friends with Foucault.