I don't know about 'optimum' growth rates for SPS. I haven't seen any reference value in terms of growth. I have seen some amazing rates on here (and on Advanced Aquarist), and most of those include successful implementations of lighting, calcium, magnesium, water quality and water flow (and feeding, if necessary). Unless you're trying to win some contest for grow-out rates or propagate for fragmentation I would say just keeping a nice, slow, steady growth is ideal in the rather limited space available in our rather small (by comparison with the ocean) tanks.
I think you make a good point in saying that you'll wait and see about your new area's water quality. I live right near the border of 3 states, and water quality can really change over the course of just a hundred miles or so. I think the major variable is how well the water companies treat their water and what they do to it when they treat it. I have some friends just down the road a little that can't keep anything for very long despite using the exact same methods countless others use in successful tanks. Of course, if you opt for a RO/DI system and keep it maintained you avoid all those problems. I
strongly recommend a RO/DI for your next system.
Personally, I would rather have a healthy, slow grow-out than a bunch of fast-growing stuff. It takes up too much of one's time to constantly frag/prune/re-aquascape a larger reef tank in addition to normal, routine maintenance. I guess if you have everything automated it wouldn't be so bad, but that's not the case in our instances. Anyway, good to see your tank doing well. I look forward to seeing what you come up with for the next tank when you move. I, too, am going to be going with a lot larger tank sometime in the next year or two. I've learned a lot from this tank already, and I'm sure you have too.
