One of the big problems I see in having a Federal Department of Education is that it makes it difficult to allow State or even Local school districts to reform differently.

I can imagine some areas embracing the things you're talking about, while other localities might be skeptical (as change is always difficult to adapt to). If those forward-thinking localities were allowed to implement reforms, then everyone could track results, and hopefully move towards those reforms that are most successful.

I know the hope is generally that with a Federal oversight, no children will be left behind (ha! :) ). But it also prevents other children from being able to make gains. And it removes too much flexibility from teachers who need it for their individual classrooms.