I have read through a bunch of threads on acceleration here and learned a lot about the pros and cons, and I now accept that it's really dependent on multiple factors and there is no one answer perfect for each year or child.
What I can offer from my own kids is that my DS asked for more, wanted more, absorbs it like crazy, and he's benefited from acceleration. DD8 goes in waves -- she picks math up easily, asks questions and learns quickly when she feels like it, but she likes to be in control. I find if she's not getting some challenge, she has coping difficulty when she does encounter frustration -- it overflows in other areas. She needed to be encouraged a little bit more. It really, really meant a lot this year to have her teacher give her higher-level material. She gained confidence that she had lost because she was frustrated with redundancy. I feel like she needs more math acceleration next year, and am exploring options, but I don't want to rush her through, so much as widen her exposure and deeper problem solving skills.
