In a nutshell, we have found that acceleration was good for a couple of months to learn something new and for the novelty of some of the material, the teacher and class. But after a few months, DS7 reported that it was "boring" and too slow. He was accelerated 3 years in math. He has asked to not do math in school next year (it is the only academic subject that he does at school - the rest we homeschool). I think that he actually preferred what he was doing at the start of the school year. He was sitting in his 2nd grade class and I sent in higher level work. I taught him the material at home (or he taught himself) and he worked on his workbook by himself at school.