A brilliant book. The style is clear and readable, and the author's evidence for his argument so powerfully marshalled that it firmly puts the ball in the court of anyone wishing to propose a cultural or genetic case for the economic and military dominance of Western culture.
One book which seeks to do so (in the specifically military sphere) is "Why the West has Won" by Victor Davis Hanson, who accuses Diamond of determinism and ignoring unique cultural variables. I think the latter has a political agenda, that capitalism and individualism are inherently superior to other cultural characteristics - but, to be fair, I am sure Diamond too, when he concludes that Caucasian Westerners have no inherent superiority to other races and cultures, is equally politically motivated.
Doesn't mean either of them is wrong, though. Read both books and see what you think.