Just pointing out in passing that the biggest problem with PC2 is that it gives a false sense of safety. The edits of anyone with reviewer privileges or higher goes straight through without stopping at pending chnages; however, there are a LOT of people with reviewer right (i.e., almost anyone who was editing at the time PC was first released) who could blithely show up,  approve a change in the queue or make a change that doesn't go in the review queue at all without being aware of all the special provisions related to this article. Full protection will prevent that; semi-protection is pretty much useless in this situation (almost everyone is autoconfirmed) and thus so is PC1.