What is this 'education as a whole' thing?
That could take a bit longer than a Mumsnet post, but I'll give it a go! I think the point of education is not (just) to pass exams and get a job, but to learn about the world around you and discover the joy of learning for its own sake, and to develop skills along the way. It frustrates me when people talk about which school subjects you 'use' in later life. In terms of subject knowledge I only 'used' one of my school subjects in my university degree and then I never 'used' any of them in my working life (except a bit of primary school maths) - but I have used the skills I learnt from my education all the time (the ability to learn, analyse, discuss, write etc). I was never going to grow up to be a scientist, or a translator, or a historian - but learning about science, and language, and history has enriched my life massively. But - although I went to a very good selective state school, I think now that my education was fairly narrowly focused on getting good grades in my exams. If you weren't on the netball A team then sport was pretty much a case of reluctantly showing your face at a PE lesson once a week and hiding at the back. If you weren't one of the music stars, then music was a fairly uninspiring hour once a week trying not to mess up playing a tambourine. My sense was that my school was happy for me to do not much outside my core subjects so that I could focus on getting top results in those (which I duly did). When I got to university it was the first time I'd met kids who'd had a different kind of education from me, and the difference was striking. They were not only more confident but seemed far more informed than me about the world beyond their subject - about sport or the arts or politics or other subjects or whatever it might be. So although my education did hugely enrich my life, I think a more rounded education would have done so even more.
At DS's school there is an expectation that every student will become involved in a wide range of things outside the core curriculum - and the quality of that wider provision is amazing (whether that's in terms of the number and availability of staff, the quality of the facilities, or the opportunities provided - eg to compete in sports matches, perform on stage, visit interesting places, listen to interesting visitors etc). As for the curriculum itself, the subjects are similar to the state alternatives of course (although a bit broader in terms of languages etc) - but it's easier to be inspired and to learn to love learning when you're in a small class, with bright and motivated kids, and with consistently excellent teachers who crucially have the time and resources (and presumably the expectation from their employer) to not only teach you the core exam knowledge but also to teach around the subject, run clubs and support groups, suggest wider reading, follow and develop their students' individual interests and so on. Also the school day is longer, which means there is just more time to fit everything in. Add to that other things like lovely food, lovely grounds, and kids from all over the world with very different backgrounds and experiences from you, and it's a pretty great place to be. Overall, the sense I get is that when a child joins the school, the school says right, we are going to make it our mission to develop every aspect of this child's education to the best of our ability, and to make sure that he/she takes the best possible advantage of everything we can offer here. I'm not suggesting that state schools don't also have that ambition, or that teachers in those schools are any less committed to their pupils' development - but I think it's generally harder to do when you have less time, less freedom, more students, more disruption and just less money.