What if it's both? I've mostly been educated by government institutions, but did go to a private school for year 7 & 8.
State all the way and I wouldnt have gone private if I had the choice for the simple reason I know I've got to where I am today by myself and not because my parents bought me my exam results/ extra time in school/list of other extra oppotunities private schools supposedly give. Also the social skills gained from mixing with people from all backgrounds at a state school - I think- is much more valuable in the real world than spending your school career with only other people from middle/upper classes. I dont think there is a lack of extra curricular activities in state schools - I go to an average one and do loads of other activities, from our pony club to debating, orchestra, netball, science club, DoE etc. The only thing people gain from being privately educated is being able to impress people by how much money their parents earn.
i went state for primary, private for secondary and state again for sixth form!
5-11: State primary
11-18: State grammar in an 11-plus council area. The system here serves people very well - most of my friends who went to high school went on to uni and one's now a teacher.