Thanks. You bring up a crucial points, as the final years of school have a big focused on preparing for public exams and applying to universities, while the earlier years are not. It is helpful to hear from different viewpoints, but I would prefer to get more feedback (directly or indirectly) from real parents that I know or contact, and compare it with what I hear from the online stories. Why? Because of survivorship bias, the sunk cost fallacy, and reporting bias. In my experiences, I hear much more parents have positive comments in MN compared to the mixed opinions when you reach out the real parents you can find (those who won't usually proactive report on MN vocally).
Another factor to keep in mind is that during the 5-7 years in secondary school, there may be changes in the school’s leadership, such as the headmaster, or intake/selection profile shift of the students and parents, that may lead to very different experiences too.