Wow I hope my SPS grows like this some day! My month old birdnest is just starting to grow a few new tips so it's very slow compared to your growth but I have less than perfect water chemistry due to algae that i'm ridding of now and I don't dose anything so I guess i'm doing decent as long as the SPS is still alive.
But man, looking at your tank, just wow...
I'm thinking you should get tank of the month or quarter with that beauty!