This paper from the Heritage Foundation summarizes the best research on the impact of school choice programs. The conclusion?
A growing body of empirical evidence demonstrates the many positive benefits of providing choice in education. Instead of policies to increase spending on the public education system, states and local school districts would better serve students by empowering parents with control over their share of education funding.
When I served four terms in the state Senate, one of the few places where you could go to always and get concrete information about real solutions was the Georgia Public Policy Foundation. That hasn’t changed. [The Foundation] is really right up there at the top of the state think tanks, so you should be very proud of the work that they are doing!