Both my kids are now at Highgate Wood School in Crouch End. This is a proper community school representing the area's demographic well - it has neither been colonised by over anxious middle class parents wishing they could 'do better' nor large groups of kids from unsupported backgrounds. The head, Patrick Cozier, is a well liked, very committed teacher (who still teaches Maths there) who is very focused on driving up standards for all.
The school suffers a bit from being very close geographically to a higher performing, exams wise, school Fortismere which is unfair since Highgate Wood has a much more eclectic intake. Highgate Wood is a good school with an even better future firmly within its grasp.