I have some statistics about the Anti-Phishing Email Reply project. Our quarantine currently has 1,906,179 messages of which 4022 were caught because of addresses on APER. All 4022 look like spam or phishing attempts. So even though APER caught only about 0.21% of our quarantined messages, the ones it did catch are potentially very nasty.
(And of the 4022 on APER, 221 of them would have scored below the spam threshold were it not for APER.) Regards, David.