I went to Summerhill School: www.summerhillschool.co.uk/
which the Sudbury school was based on (it is not "the first of its kind" as stated in Wiki).

I went there for 8 years and loved it. My brother probably would have been diagnosed with adhd, oppositional, anger issues etc if they did that back then. We tried 4 schools ranging from straight public to co-op alternative before my mom finally decided for the sake of his happiness and everyone else's sanity my brother should go to Summerhill. I demanded to go to on the grounds that it was unfair to send him to England and not me. My mom was right, my brother thrived there (and so did I).

It was a very happy childhood, and I go to the 5 year reunions whenever I can. I wish I could have afforded to send my girls there. Most of my friends from there are now happy and well-adjusted adults, some are now doctors, dentists, chiropractors, teachers, restaurant owners, writers, musicians, producers etc.

When I went we averaged 60-80 students, we did not have cell phones, TVs or computers so I don't know how technology might have changed the dynamic for today's students but really, I think those things are escapes and at Summerhill there was nothing to want to escape from. If we got bored, we would round up other kids for a game or climb a tree, go have an adventure in the woods or hang out in the art room or woodworking shop or dance. Ahhh the good old days!