St. Pauli,
I have mentioned in earlier posts that we switched schools at a much younger age (pre-school), however I can relate to your "aha" moment.

Mine came within the first week of switching. I would pull up in the carpool line and brace myself for the litany of (somewhat minor, in my opinion, but still stressful to hear) behavioral complaints I used to receive daily from dd's previous teacher. And at the new school, the teacher would just say, "DD had another great day. She's fitting right in here."

The behavior problems went away overnight when she was put in a more appropriate environment, with teachers who understood her and peers to whom she could relate.

I think there are flaws at every school. And certainly there are things I would change if I could. However, I think you can't underestimate the impact of a good peer group.