I read his brief "Why is this the best anti spam", and that is making me ask "why would I bother?", along with the licensing.

Looking through the code and description, I understand it doesn't remove the spam, it merely hides it, with a mouseover function. It's a good idea, but not what I'm looking for :)
The one I'm currently using is completely removing the entire post, which is perfect. Also, the rare occasion of a false positive doesn't bother me in a place like 4chan.

And the author should review the spam strings, I count multiple doubles in there. Many of them are also obsolete (doesn't occur on any of the boards, as far as I have seen anyway)

There are a lot of other boards on 4chan you know.