My DD13 is a very successful and fairly well-adjusted high school junior this year.
She was homeschooled from ages 4-ish (well, we sort of followed her lead and interests and did a kind of Montessori-at-home thing) to six, when she began rebelling against what I asked her to do and refusing to work on relative weaknesses. At that point, we enrolled her in a brand new virtual charter school. As a third grader. Mid-year. Given that she had, at 6.5 yo, taken an out-of-level CAT-5 and performed at the ceilings in every area, this was viewed by all concerned as a relatively "conservative" acceleration.
She handily finished the entire year's curriculum in about 6 weeks. (This was Calvert's 3rd grade, incidentally.)
The following year, she completed both 4th and 5th grade even though she missed about 8 weeks of school due to medical concerns, and therefore at 8.2 yo, she entered 6th grade the year that the school began assembling a "gifted and talented" program.
Most recently, she "skipped" 10th grade entirely and went from 9th to 11th after last year-- this was fine since her credit accumulation from middle school was a year ahead of her graduation cohort anyway.
It's been a little nerve-wracking for us in that we've had nagging worries about executive function development-- most seriously in the 10 and 11yo ages, and easing some now.
So I'd say if your child clearly NEEDS acceleration, do it. BUT-- recognize what you're trading. Extracurriculars, my child is competing head-to-head with peers who are 3-5 years older than she is. Also realize that acceleration alone isn't going to solve the problems. My daughter has NEVER been fully challenged academically, and this has led to other problems like perfectionism and maladaptive coping (procrastination, etc.). It's a bit better this year because of her load of extracurriculars, community activities and AP coursework. But only "better." She regards AP Literature (which is crushing most of her academic peers) as one of her "easy" classes. She's enjoying it, but it's not really at the pace or level that she needs in order to really 'stretch' as a learner, if that makes sense. It would have been PERFECT for her about three years ago, but then again, there was a lack of life-experience then that would have made some of the analysis bit of things challenging.
It's just plain HARD to be this asynchronous, and there is no real way to make that part of things go away.
I think that it's important to realize that acceleration is not "the" answer, but it's
part of a good answer, in a lot of instances.
