this thread is old enough where you've already made your decision i am sure. but we grade skipped our son into k a few years ago. BEST.DECISION.EVER. he starts second grade tomorrow. so he is not the tallest kid in class, but he is still at the top academically, he LOVES school, he is very popular, and he still has to have support in all subjects to accelerate even more. when i see the grade he is supposed to be in walk by, i can't imagine him fitting in there AT ALL. he has no age or academic peers in his class, but that is what the gifted saturday program is for at our local college.
kindergarten was a difficult adjustment for him since he had never been to preschool, but he made it.
