OK, I just read through Are High-Quality Schools Enough to Close the Achievement Gap? Evidence from a Bold Social Experiment in Harlem. By my reading, the key point is that based soley on high-stakes English and math tests, the only interventions in the Harlem Childrens' Zone that have a substantial effect are the schools. What makes this study different than similar ones is that they can compare the scores of kids from inside the zone and outside, and find that there is not a significant difference.
I'm not enough of a statistician to say whether or not the amount of growth shown at the Promise Academy schools is significantly greater than that at older schools which Promise Academy explicitly emulates. If it is true, we're left with a mystery. What are they doing differently? Fryer claims to show it is not because of the other measures in the Zone.
If you buy this study, it is an argument against replicating the Children's Zone.