The key to learning is setting high expectations - starting where you want the students to be rather than where they are and rapidly moving to achieve it.
Behaviour needs strong leadership so teachers are not left isolated and unable to share any concerns.
When schools competed, successful practice couldn't be shared and developed. That was breaking down under the last goverment. Now we are heading that way again; without LAs to lead the sharing and support. Schools need exam success, but they also need to develop reflection and breadth for their students to ensure flexibility.
I have moved to Kent and am glad my children went through a fully comprehensive system. To be a failure at 11 is disastrous.