Bayesian Filter Testing?

pu33y asks: "Since the publication of Paul Graham's A Plan For Spam, several programs that perform Bayesian filtering having become available, including CRM114 and Bogofilter. But missing is any serious testing to see how they perform in relation to themselves and to other, non-Bayesian filters.Searching Google has turned up nothing and when I asked Paul Graham, he was unaware of any such testing, as well. Can anyone point to any such testing or provide the results of their own personal experiences with Bayesian filters?"