Two things are true. (1) If your child is ready for more advanced academics you generally should want to accelerate. (2) If your child is put into a higher grade, then it will count against them in some tests and competitions.
I believe that if (2) is the price you have to pay to get appropriate academic acceleration, then it's still worth it. But (hypocritically?) we got the best of both worlds: single subject acceleration in every subject, without whole grade acceleration
We're in a virtual school. DS7 is in grade 2 (standard grade for age), but all his subjects are grades 3 to 6. We could have put him in grade 3, but we decided not to because (a) he can accelerate in each single subject regardless of his "official" grade level, (b) he would be penalized in some tests and competitions (yes, we most definitely considered this and it was a major factor in our decision; we couldn't deprive him of the chance to get the best possible results), and (c) he may not go to college early, to give him the best chance of being competitive at elite universities, so instead he'll accumulate a lot of college credit while in high school.
