I've used and loved this plugin for a long time. Sometime this last summer, an 'update' was released, with no heads up, which basically destroyed this plugin. It reduced the spam protection, and apparently added it to its paid version. This is acknowledged by the author in the support pages for this plugin.
I contacted the author about getting a ton of spam after the upgrade and he said that his paid plugin 'simple comments' has stronger protection and has more features etc, so I should buy that one.
I think we deserved a little heads up or warning on the update release notes, sth like 'the spam protection on this next update is reduced, install at your own risk etc'. Especially those of us with a low budget and and cannot afford to pay an annual fee for licences. Now I can't even revert back to the old version that had the good protection.
So I find myself looking for a decent FREE spam protection plugin again.