So far it seems like the results are... not really. But what's interesting is how sensitive the answer can depend on what study you choose and what data it is based on. I am trying to focus on the ones which control for the student demographics. This seems to me to be the best way to see if, for an individual student, they will do better at another school.
The difficult part of endeavors of this sort is to really find what is the reasonable "consensus" of the current science. An idea that was brought up at TAM8 is that, not being a scientist, my job is not to attempt to a "analyze" the science that is out there, but simply present it. But a small amount of meta-analysis does have to occur in trying to determine what the most up to date and accepted research is. It may be that I am starting my research during a "tipping point" in the consensus. How am I to know? It's both frustrating and rewarding to attempt to find and distill research down to present to others.
There is a wide range of research on this topic, so I need to be very careful in my choices and, as always, fully back up any of my findings.