I don't even attempt to make statements regarding their draw, my window of it is pretty small, basically when they come close to Pittsburgh, I go see them. They have played the same place two tours in a row (DT12 tour and TA tour) and it was sold out both times. Before that, they played an outdoor venue that doesn't exist anymore, but probably drew about the same. Going back further than that, I saw them open for IM and do a one-off on that tour.
Actually now that I think of it, the smallest crowd I ever saw them play to was in Buffalo on the Progressive Nation tour in support of SC. They played the same size theater there that they have been playing in Pittsburgh, only they didn't fill it on that tour.