Oh, I just should add a note to answer your question. My elder son, who is the one who has been in every schooling situation available, has been grade accelerated twice.We would have loved a flexible subject acceleration (which we did while homeschooling) but that never worked for our schools. The parochial school skipped him once and would have worked if the principals plan for further subject acceleration had been accepted by the teacher, but that did not pan out and eventually led to some very bad teacher attitude issues. After homeschooling one more year,my son was allowed a second skip into a public charter school (with proper documentation and with the caveat that he could be pushed back if he did not perform academically or socially). He was on the high honor roll in that school but the school was very inflexible and just did not foster any love of learning...it was more like a boot camp.
In retrospect, I think that grade accel has worked for this child but I would have loved more flexibility like I know works for friends across the country. If at age 10 he could be allowed to work at his own pace and be in classes with ages 11 or 12 to 16 he would be very happy.Homeschooling should accomplish this but did not pan out socially or academically in our geographic location (and my son really likes to be in classes, so we had to find some of those situations that were open to young kids). He is a newly-minted 10 year old who will be in 7th graders who are 13 and above. But that does not bother him and has yet to become an issue for us.