"Many children are better off in the state sector, those who need parenting by the teachers, those who's parents need educating alongside the children, those who have SEN that can't be resolved with an extra couple of hours extra tuition etc."
Actually, those children would probably be the ones who would benefit most from the small class sizes and extra money available in the private system (though obviously the extra money might need to be allocated in a slightly different way to meet the needs of this somewhat different cohort). It's sad that they are the children least likely to access the private sector...
Heswall, I am not trying to make grand 'one sector vs another' comparisons. The point I am trying to make is that the cost / benefit balance is different depending on the precise schools available in your area, and also on the needs of your specific children. I could easily have been in your position - DS had a bad time in his first stae primary, so I removed him. Had we stayed in the same area, the best option for him may well have been private, as in that area there are some very good private primaries / preps [though they were a bit
about DS's (then) selective mutism]. I might well have also been making strong comments about state education, based on my child's bad experience.
As it happened, we moved, and in the area we now live there are very good state primaries, and not such good private primaries, so after visiting all the options we chose the former. I am not claiming that my DC's school is better than Habs or Colet Court (both of which are hundreds of miles away) - I am making the much more minor claim that in comparing LOCAL schools, for my particular children and their needs, their current school is at least as good as the LOCAL private primaries, especially when their 'extra curricular' needs can be met so well in the community around the school.
The variation within each sector means that there is no 'clear water' between 'all state schools' and 'all private schools'. There is a huge gap between the worst state schools and the best private schools. There is also a gap between the worst private schools and the best state schools, as well as the big gaps between the best and worst in each sector. Comparisons need to be made on a 'school by school' level, not at a sector level.