LoneRebel
Emperor
I plant manufactories early game because the hammers add up that way and because wonders are cheaper earlier in the game. In fact I don't even use them to rush wonders until the wonders cost at least 1000 hammers. One exception is if my capital can't build Macchu Picchu or Neuschwanstein but I have a less developed city that can, then I rush it there. My thinking is that a manufactory planted early, at 4 hammers per turn, will add up to 800 hammers in 200 turns. And that's without even factoring in the chemistry bonus and the percentage bonuses from workshop/windmill/factory/power plants. That would easily bring the total over 1000, equal to the cost of the late game wonders. Earlier wonders just aren't worth enough to justify using a GE on them in my opinion.