I've been putting together a level using Faith Plates and I'm somewhat confused at the existance of an instance in the SDK called faithplate_black_impostor, which as far as I can tell is no different from faithplate_black. The same applies for the white and dirty floor versions. Can anyone tell me if there is a non-obvious difference in these instances?

i think than the false trow you in a diferent direction whan its looking

The throwing action is done purely by a seperate catapult_trigger volume and has nothing to do with the visual models.