I think now is a good time to have a bit of a scare @Oblomov23 . DD1 got a horrific score in RE at the end of year 10- when she memorably forgot the word muslim and instead wrote 'people who follow Islam' every single time instead - which slowed her up somewhat! I wouldn't mind, but it's an incredibly diverse school, she has many muslim friends and teachers, and we're regular churchgoers. She got a 9 in the real thing though - fingers crossed your DS will have a similar epiphany...though it was only a half GCSE anyway at DD's school so not so much to learn.
Probably saying little is the best policy - he'll know what you think.
In terms of reports, DD2's came without number grades on it. She had been given them on the exam papers themselves but for some reason we didn't get them like that. It was instead written and then with letter grades. Everything was an A or A+ so I'm assuming A is a 7 and A+ 8 and 9 - but it's hard to tell what they really mean.
Teachers mostly seem to feel she is 'driven' and 'polite' - I think this is just in context of her coming from a school where she had to manage her own time and progress if she wanted to do well and where you would have got a detention if you hadn't signed off your emails with Kind Regards.
Obviously we were very pleased with her, but it comes in the context that she's dropped three GCSEs this year because she's at music school. She doesn't even do a language, and is Combined not Triple science and no further maths.
We're aware that she's going to have to manage her GCSE workload at the same time as a LOT of music next year - they won't let up because of exams. And there's not much we can do about helping her from 100 miles away if it does go wrong - I'm already contemplating booking a hotel for the first couple of nights nearby in case of massive upset.
She has done some revision this week so far, but not masses - definitely concentrating on her favourite subjects rather than the ones she actually needs to revise!