The Caroline Hoxby vouchers debate

Is Caroline Hoxby's defense of school vouchers hopelessly flawed in its data work?  I doubt it, but I have not been following this debate.  Here is the recent and excellent WSJ article on the spat; the link does not require a subscription.  Excerpt:

Five years ago Harvard's Caroline Hoxby, a rising star in economics, wrote a paper that reached an unusual conclusion: Cities with more streams tended to have schools with higher test scores.

Today her work is a widely cited landmark in the fierce national debate over free-market competition in public schools. And it's at the center of a bitter dispute with another economist that is riveting social scientists across the country.

Her adversary is Jesse Rothstein, a young professor at Princeton, who says her study is full of flaws. In a rebuttal to her critic, Dr. Hoxby wrote of his work: "Every claim is wrong." She has also accused him of ideological bias. Dr. Rothstein, in turn, says she resorts to "name-calling" and "ad hominem attacks" on him.

For commentary, try this Mahalanobis post, or this from MaxSpeak.  Here is a critical take on Hoxby.  Here is The Lowest Deep on the debate.  Here is Brad DeLong, my view is closest to his.