First, the negatives. The book could have been edited better and one is occasionally thrown by paragraphs that seem to have been inserted in quite at random (I am thinking of the chunks of history, mainly). Plus, you either buy the conceit very quickly and accept the narrator's worldview or you just won't get on with it. Basically, if you haven't laughed by the end of the first chapter, you won't like the rest, so be warned.
Now the positives. This is definitely not your average travel memoir! It's witty, acerbic, full of the writer's unique personality and Weltanschuung. In a way, not that much happens and there are times when the moaning and planning to escape all becomes a bit de trop. But that is part of the deal - you are spending time with the forceful and uncompromising p.o.v. of a born writer, who is great on observation, capturing local colour and the deflation of pomposity, especially his own. I laughed out loud quite a few times and finished it in more or less one sitting, which I think says a lot.
Read if: you appreciate some of both the more and less appealing characteristics of the English
Don't read if: you have a starry eyed view of the Third World, have no sense of humour, and are a fan of Ethiopian cuisine!