A lot of people seemed to like the replicators on SG-1. However, it seems people were tired of them come Atlantis (Asurans) and The Ark of Truth. How come? Personally, I never grew tired of them. They reminded me of the Borg from Star Trek in that they were relentless and nearly impossible to defeat. Some people say that The Ark of Truth should have been exclusively about the Ori. However, why not bring in the replicators? Morena Baccarin (Adria) was only available for one day of filming, so perhaps that resulted in a larger replicator subplot than was originally intended? Then there's the Asurans from Atlantis. How come the expedition kept calling them the replicators? They really weren't replicators. The Asurans simply wished to be left alone, or was that the Wraith's doing? Regardless, I understood the threat to Atlantis, by why would they go gunning for Earth? That assumption in "First Strike" never made sense to me. Anyway, the Goa'uld went on for eight years, the Ori two years, and the Replicators ten episodes and a movie. How is that overused? The Wraith were Atlantis's central enemy for all five seasons. The Asurans were only there for nine episodes. Again, overused, really?