My son went to a charter HS. It was, by far, one of the best schools I've been around and was damn close to the private school I went to in FL that now runs $13K a year. Too bad the apple didn't fall far from the tree in not taking advantage of opportunities.
HOWEVER, I have said this a gazillion times - it's the parental involvement that matters. This was a public school before it became a charter school and the same high level of education, teachers, staff, etc. was there then also.
Another HOWEVER, the administration of that school in Sharky's report should all be fired.