A long thread . One where if one makes generalisations, they are considered
"sweeping" and therefore invalid, yet, unless one makes such generalisations, it is impossible to answer the OP's question. You have by definition to accept the every one ( school ) is unique situation and cannot therefore state any arguments in favour of independent schools ( by definition a generalisation).
I have taught in university. I have taught in state schools - good and bad - and in independents. My earlier contribution stated simply that you pay for " social exclusion" , to which someone then suggested far more cultural diversity. You cannot win.
I still state it - the main argument in favour of independent schools
(sweeping generalisation coming) is that you pay for social exclusion. Or to be non PC, you pay to have your child educated in a middle class environment with middle class children by middle class teachers especially if you are middle class yourself. It reinforces all your own social and attitude values in a stroke. Middle classness does not know cultural or ethnic boundaries. Whether from Hong Kong or Bejjing , Moldovia or Middlewhich UK , its the same.
Many have pointed to how children in indipendents "speak better" - are more appropriately behaved etc. Yes. But its not because we have better standards of discipline its because the children arrive with certain values already in place. We just reinforce them.
We have smaller classes. That means that the odd rogue behaviour is picked up on and dealt with quickly. The fact there is very little poor behaviour also means we have more time to teach. That itself feeds into higher achievements. Further in most independents there is an ethos for doing well, for being academic ( or sporty, or arty etc) but there is an ethos of appreciation. No one will find themselves being targetted or cold shouldered for being different or being good at something. You cannot under estimate the power of social conformity and peer group conformity in this regard. I have found it to be a major basic difference between state schools ( antoher generalisation there) and independent ones. In state schools kids conform by being the same. Being clever is not " cool", so if you are clever, the tendency is to hold or pull vack. That in the end becomes an ethic which becomes instilled and affects final achievements.
If you take an educational aspirational child, one with middle class values and put them in state schools, with best will in the world, they gravitate away from that culture to the more common ( I mean majority) one. I myself went to state bog standard school because my mother had priciples ( socialist ones!) back in the 1960's) . It is my greatest regret she did. I was a middle class fish out of water . I was bombarded on all sides with comments. I was even sent to Coventry for three years for being " too clever" and refusing to pull my EXAM PERFORMACE TO ALOW SOMEONE ELSE TO GET FIRST PLACE AND THUS FORM PRIZE . Yes, thats how it was. To fit in I had to " go home to tea" ( we had dinner) . I had to " mess around" I had been taught to get my head down and stay out of trouble - My brother got a private school education , mother having figured her mistake with me! You think this doesnt happen now? Think again.
The language skills so natural to children in independents are great boost in achievement anyway - especially in exams. The social networking does have an effect in later life, no one can deny it ( OK , so its not fair) but above that, the one thing I have seen which cannot be equalled in even a grammar school education from the 1950's is the effortless ease with which those who are educated in independent schools tackle all and any situation. Their social skills and confidence Its part of the parcel.
First ime buyers into the independent system are often aspirational. But their kids either fit in or they leave. If they fit in, it will be because they adopt quickly to the cultural values. I have taught some children who do not fit into this middle class value. They have proven disruptive even for us. Yet in state schools they have often been described as quiet and hard working later.
There are differences in the way teaching is done. In most state schools a lot of teaching is behaviour management ( another generalisation but true nonetheless). Children in such schools have been subject to every whim of educational research and much of it is pop psychology that simply doesnt work. They are one giant ongoing experiment.
If you think there are no behaviour problems in sixth form in state schools - think again. Certainly many kids in state schools, because they havent got the attitude and cultual valeus and most importanly language skills do not have appropriate skills for A level .
In independents there are no behaviour problems at all , or minor disruption is shot shrt quickly. Throughout the school.
Similarly we tend not to adopt policies of inclusion. We do expel students.
Thats what you pay for.
I know there is a view that bright children will do well anywhere. Thats probably true. However, because of the recent recession a number ( first time buyers and boarderline) of chidren from my independent school have completed sixth form in state schools or in FE Colleges. True to form, these children have been hailed as " OUR star students" They do not tell you that said students came from the local independent.
As for whether the teachers are different in the two schools? I dont know. I have been in all . When I went back to teaching and went into my current school I spoke to a friend ( old grammar school educated and from Oxbridge). He said to count the number of Oxbridge graduates on the staff role and then add how many Ph.D's were on staff . In most state schools you will not find that. In fact, having worked in a state school, I have also found my Ph.D snarled at and sniped about and often not used at all ( ignored). Or you get the culture which has to ask why you are called "DR" when you arent one ( ie a medical Dr.) or why you teaching and not doing medicine! Trying to explain is almost impossible. They have no culture for it.
In independent schools the pupils call me "Dr Jabed" . They dont bat an eyelid at it. They understand it. I have occassionally been asked what my specialism was ( by sixth formers) . I never had that in a state school.
OK, thats all from me.