As Kylerean said, the +100% GPP birth rate really isn't that big of a deal. Industrial helps for wonder production, but bigger factors involve say... grabbing religions into your desired legendary cities.
I've done the "bigger empire" legendary culture victory that kylerean mentioned--although it wasn't really the objective at the time. I find that multiple religions in your legendary cities is key, as each religion's monastary gives +50% culture.
I've done the "bigger empire" legendary culture victory that kylerean mentioned--although it wasn't really the objective at the time. I find that multiple religions in your legendary cities is key, as each religion's monastary gives +50% culture.