SPS growth is hard to predict unless you are familiar with that exact coral. I've had two of the same coral and one grow faster than the other, probably due to a flow or lighting difference...though minimal at best.
A good point is how the starlight acro in my tank actually grows faster than my pocilloporas.
Though even with that said, nothing is faster than a birds nest when it comes to SPS. The green tip in my tank is just massive, to the point I wish it wasn't there anymore.