I had read John Searle's long, well-written and thoughtful review of Humphrey's book in the NYRB when it came out in October 2006, and now I've read Paul Broks's shorter and less critical (but just as well-written) review of the same book in Prospect magazine.
Both reviews suggest to me that the book is a worthwhile read. Humphrey's distinction between 'perception' and 'sensation', and the counter-intuitive proposition that perception is unconscious and sensation of our perception is what creates "consciousness" and the qualia is really worth pondering, I think. All that remains is to find some time I can steal.