I think Class 8 is more suitable. After all, the learning atmosphere is very important for a student. Besides, you said that the head teacher of Class 8 is a young teacher. Generally, young teachers are easy to communicate, unlike qualified teachers who are a little sophisticated and will not treat students equally. Moreover, the key to learning this thing is to rely on yourself. A good teacher doesn't mean a good class. Similarly, young teachers don't mean they don't teach well. So, I hope my advice can help you.