My own 2¢: I've taught and tutored math and science in a variety of public, private, and charter schools. I went to several non-standard schools myself, so I thought positively of charter schools in general...until I had to teach students there. I always felt less productive in these situations for frustrating reasons like this:

Free-standing charter schools often bite off more than they can chew. The presumption is that without the bureaucratic restraints of the public school system and the teacher unions, charter schools can provide better education at lower cost. But the problem with failing public schools is that they often lack both resources and skilled, experienced teachers. While there are obvious exceptions, some charter schools embark on a path that simply recreates the failures of the schools they were developed to replace.

Americans are so determined to get something for nothing that they are always getting a bargain, but never paying attention to the hidden price of the bargain. If we were willing to pay adequately for public services, we wouldn't have to find magic substitutions that also fail.