DS10 couldn't be mainstreamed in a regular public school program because he was so out there intellectually but (IMO) not socially & emotionally mature enough to be skipped during the early grades.

We've always enrolled DS10 in gifted schools that accelerate but keep the kids with age peers so we've never done a full grade skip. From K-3 he was in a program that accelerated him 3 yrs in math & reading, 1 yr for the rest & he was with his age peers. In his new school he does have a grade skip for math + acceleration (to equal a 3 yr acceleration) and he really enjoyed being with the older kids last year. At this point i would consider a grade skip for him but not when he was younger.