Just to update this thread, the Moderator Checkpoint System has been helping us moderate AVForums nicely since March 2008. There has been one annoying bug which produces a -1 checked post count, but apart from that it's been solid. The moderators have found the system invaluable for identifying which threads and posts require checking. It makes the use of their time much more efficient.
As we leave vBulletin behind this summer, five and a half years after the original idea, the
Moderator Checkpoint System has been released at Xenforo.