If you read that last post of his, you'll notice the entire basis of his diatribe is simply that he happens not to accept a premise of the zombie argument. He's quite explicit about this:
A good argument starts from premises that everyone (in the debate) thinks are true and then show[s] that because of that they are committed to some other claim.
Anything else - the slightest hint of controversy - and an argument is ipso facto "crappy". This is a view which calls for no further refutation than its own clear statement.
It is possible to have a good (reasonable, respectable) argument that does not command universal assent. Indeed, it is even possible to respect an argument that you ultimately judge to be unsound. (I hold G.A. Cohen's argument against utilitarianism in high esteem, for example.) So I propose that we should instead assess arguments according to how well they advance the dialectic. So long as there are some opponents who are antecedently disposed to accept the premises of your argument, then it will have some rational purchase on them. A truly question-begging argument, on the contrary, is one that could not reasonably sway anyone who did not already accept the conclusion (because the conclusion is transparently contained within the premises in a way which makes the reasoning vacuous).
It should now be clear that the zombie argument is not, in fact, question begging. It has two controversial premises, but each is accepted by many prominent materialists. Moreover, there are at least a fair number of materialists-by-default, like my past self, who are disposed to find both premises very plausible, and hence to be rationally persuaded by the argument to reject materialism. It isn't vacuous, it begins from premises that many people -- including those who don't antecedently accept the conclusion -- find compelling, and from which the conclusion validly follows. What more could you ask for?
Now, I don't think it's a knock-down argument, since the premises are (as always) open to question. Indeed, I was very explicit in my overview post that I think people can reasonably disagree about whether to ultimately accept the zombie argument or not. But even one who ultimately rejects the argument should be able to recognize that it has some rational force (and certainly isn't 'question-begging' on any sane conception). Apparently that makes me a "fanatical property dualist". Go figure.