This is all good information for us as well as we consider whether subject acceleration or whole grade skip is best.
I will say, though, that neither dd nor I regrets at all skipping her. We did try subject acceleration before the skip and it wasn't enough. Even if she places lower in her class than she would have without the skip, she is far better placed both socially and academically and we would do it again if we had to do it over.
I mention that b/c I don't want people to think that I am anti-skip nor try to talk anyone out of it. When the alternative is totally unacceptable or, like others mention, your child is miserable, it is sometimes the best thing to do. We tried everything else before the skip: three different elementary schools, subject acceleration, homeschooling briefly when one year was unbearably bad, and GT pull out classes that met daily and replaced core subjects. I think that, when you get to the point that you've tried it all and are still desperately searching for something better b/c it isn't coming close to working, you're at the point of trying something more radical like a skip.
