Calc BC can be so different depending on who is taking it and who is teaching it. For my older son Calc BC was a super easy class (he took it as a junior too) - helped by the fact that he’s a math whiz and the teacher told them to do as much homework as they felt they needed to master the material, but he wasn’t going to check that they did every problem in the book. My younger son’s teacher wasn’t so laissez-faire so, he did have to do the homework. And he’s a kid who really needs a lot of drill to remember math facts. He’s got a good math mind, but can’t remember his multiplication tables! He did fine too with a full schedule, but it was a lot more work for him. I suspect your kid would do fine in BC - I like the idea of talking to other kids about what it was like for them in our school.