My ds is a boarding cathedral chorister.
It is OK if ds likes singing and you are prepared to let the cathedral use his voice without any consideration for the effect that a chorister's life may have on his social, psychological and academic well-being, and the following:
It is OK if ds is well-above average academically and can work fast and completely independently - they get no support with homework and have a very limited time for it. My ds is now failing catastrophically and has completely lost his self-confidence. The school cannot realistically provide the help he needs - no time.
It is OK if you live very nearby. They get 'let out' for only short periods of time (measured in hours and very haphazard) - so living within walking distance of the cathedral is best, which might sound surprising, but true. We do not live nearby and much family time = mooching around in coffee shops near the cathedral. I am not sure if these desperate attempts to maintain a bond with a child and a communication channel are the kind of experience that represent 'happy family memories'.
It is OK if you don't mind losing your son to complete strangers at the age of 8. Once in the system 99% continue boarding until they leave school aged 18. House parents have over 50 boys to care for and no matter how wonderful they are, do they know your ds better than you? Can they really see everything that goes on? My ds was bullied for over a year and nobody noticed.
It is OK if the boarding house culture is similar to that of the family culture. Do they share your tastes? How neurotic as a mother are you? Eg. My ds was an avid reader, but time for reading at school is only 15 minutes a day at most. Boarding does not seem to be conducive to reading - no place or time for it. Eg. my ds hates watching sport. There is one TV and team sports are popular. Eg. I always limited computer gaming. Now there are no limits on this, apart from the time available for it. Eg. Radio 1. They listen to it every morning. At home, Radio 4/3. My ds now often enthuses about the latest (often crappy) hit he has heard. Eg. food. I always chose food carefully for my ds - plenty of fresh fruit and vegetables - and did what I could to develop healthy eating habits. At school, they have cheap snacks regularly - biscuits - and keep sweets in their room.
It is OK if you are poor, but only if your son is either academically brilliant and/or passionate about music (can play an orchestral instrument well) - scholarships and bursary should follow in secondary school.
It is OK if your son is used to school food and won't suffer from eating it 24/7. My ds used to be very physically fit and healthy. Now, neither. Has had a racking cough for over a year and cannot even perform as well athletically as he could 2 years ago even though he is taller! Just watching him running around now - feebly - is sad.
It is OK if you have many children and if your child is extrovert. First, you will miss the absence of one child less if you have others at home. Also, the siblings left at home will grieve less over the loss of one if there are others. Secondly, a child from a large family is used to fighting for survival 24/7. If your ds is an only child, he may not have the social skills to cope easily in an intensely competitive boarding house environment and he may find the transition acutely stressful. As a result, his health and ability to work may suffer quite shockingly. And your child will get no relief - there is no home-time or escape - and you cannot help them. They must learn to cope alone. The odd rushed phone call is painfully inadequate.
It is OK if the other children are from a similar social background - most from come from well-educated middle-class families and are well-acquainted with boarding schools. The parents do not consider sending children away aged 8 a parenting failure. They consider it a privilege and an opportunity - for what one might wonder!
It is OK if your son does not need a lot of down time. During the week, my ds has a couple of hours off on Wednesdays and a few on Sundays (because usually 2 services -sometimes in the morning only, sometimes in the morning and afternoon.) Saturdays are busy - school, sport and services. Holidays are short. About 5 days after Xmas. About 2 weeks at Easter. And a shorter summer holiday also. This is because the boys sing during each holiday and have to work during 2 holidays - preparing for exams. Also, instrumental music practice is necessary every holiday if you require a music scholarship for secondary school.
To sum up, ideally, to be a happy chorister, your son is academically excellent, a great singer, very musical, extrovert, lives within walking distance of the cathedral and has a brother or sister at home with whom he has learnt to compete with. You do not need to be rich.