This depends very much on your options. Given that AP courses have honor points in high school but not in middle school, there are real GPA tradeoffs in taking high school math early. However, there are other concerns as most NC districts do not have much math beyond calculus, although NCSSM would be an option eventually. And there aren't many peers taking calculus in middle school, so your child needs to be ready to learn independently.

We elected for math now, and will run out of options for high school math before high school starts. I think it was a good decision for my child, who was rapidly coming to detest math before being allowed to have some challenge. I don't really care about GPA issues, but I am worried about what to do for math in high school.