I am in year 13 at a maths school atm, and moving here is one of the best decisions I have made. I've just been speaking to my friend, and he said that maths school had been the best two years of his life, and I'm pretty sure if I asked anyone at school they would say the same thing. I would say, only apply if you really like maths, because you will be in an environment full of people who love it and are super good at it (like I'm sure you are). The dynamics are similar to any other school environment; people are sociable, and meet up outside of school go to parties etc., so don't be worried about missing out on sixth-form/college life because you will find a load of people very similar to you and it is very easy to make friends. There is also a big emphasis on everything not-maths too, like wellbeing and culture (for example, recently we went on a (free) school trip to see an England football game at Wembley!) If you have any specific questions just lmk!!