Background: public school K-5, private school 6-12. Also have a MA in Teaching, and spent two years teaching in public schools (1 year in a high school, one in middle school) as part of that degree.
Like many others have posted, school was a bore for me. Part of the reason I transitioned to a private school was for the additional academic challenges afforded there. My senior year of high school I only took two classes and already had the equivalent of a full year of college credits between AP exams and dual-enrollment. With the exception of the AP courses, I spent most of my time playing cards with a few similarly inclined friends (Rook was our game of choice).
Since I didn't go to public middle or high school I don't have a direct comparison to say if things have changed, but with my experience teaching in those settings I do begin question whether sending them to a public school actually be harmful. Apathetic (or plain burned-out) teachers, apathetic administration, and genuinely dangerous fellow "students". School may not be a prison, but far too many of the kids attending need to be in one.
Obviously, not all schools are the same. The school our daughters would go to is rated highly, and as a major contributing factor in choosing where to live. Still, I struggle with the decision. I will likely see if I can take a few days and "shadow" to see what things are like...