I am in australia, New south wales, and have a beautiful duranta tree. It is very robust and easily propogated from a large branch stuck in the ground.
Although i havent had any seedlings come up i understand it wont be long before it is put on the noxious weeds list because of seeds being dropped on the forest by birds.
PS it doesnt bloom all year here and we are sub tropical. See we call her geisha girl. the Golden Dew drops refers to those seeds which are allegedly a problem. I havent seen any birds remotely attracted to these seeds.