I dont know about aggression but some definately grow faster than others. there are quite a few different ones out there:
Seriatopora hystrix (what typically comes to mind when someone refers to birdsnest)
Seriatopora guttatus (ORA green, bird of paradise or Dr F&S orange guttatus)
Seriatopora stellata (thick branch. I've had this. grows slower than the other birdsnest)
Seriatopora caliendrum (another thick branch variation).