I'm not a teacher - but have read this thread with interest. My 2 DDs have been educated in the state system so far - one is in Year 7 and has just started secondary school, and the other is in Year 6 and will start secondary school next September.
We live in a fairly affluent area - with the local secondary school scoring about 70%, and a "Good" Ofsted. It's also the school I went to - so I have some fond, and not so-fond memories!
However, although my DDs' junior school was excellent, and both girls have always enjoyed school, my older DD "hates" her new school. She certainly misses some of her old friends - who went to a number of different schools - but she's quite sociable and has made some new friends - plus is playing for the school Netball team and goes to drama club and singing - so seems to be making an effort. Her main complaint is that the majority of the lessons are boring, and she mentions things like having 3 French sessions a week, with 3 different French teachers. Out of 4 English sessions a week, 2 of them seem to be spent doing silent reading. Her homework seems much easier (colouring this weekend!!) and there is less of it than her younger sister has - and she doesn't have huge amounts.
In addition she clearly finds the playground intimidating, and she and her friends go to the library at lunchtimes. When I went for parents' evening(mid-afternoon) some children were picking up gravel and threatening to throw it at others.
I'm surprised and somewhat disappointed and am on the verge of sending her and her younger sister (in due course) to a local girls' school. Having gone to an Open Day I'm swayed by the smaller class sizes - 18, better facilities, single sex education - I think girls are more adventurous without boys in the classroom , at 12 my daughter could pass for 15 easily (I remember being very distracted by boys at school), and just a nicer "feeling".
It won't be easy to find the money, but we can, and at the moment I can't think of anything I'd rather spend it on.
Both my DDs are, I would say, above averagely intelligent - but by no means top of the class, my younger daughter particularly is extremely quiet in class and thinks more "out of the box" and is quite creative. Whilst I think both would do "OK" in the state school and would almost certainly get 5 GCSEs at A-C, given that I am fortunate to have the choice - I'd like them to do better than "OK".
DS is just one, and we will probably have him follow the girls in attending state schools initially and then take a view later on - depending on what seems right for him at the time.