I can't give any advice, but I can say my DH and I share your concern!! We have a meeting with our school next week about grade acceleration for DD9. We swing between worry about maturity issues if the skip happens and worry about what will happen if DD doesn't move up. Our DD is very vocal about how awful school is!! She didn't mention it until the end of 3rd grade (last Spring).I was shocked by how much she disliked school, and how unhappy she said she had been for such a long time.
After I read some posts here I will be working on the Iowa Acceleration Scale that some have mentioned. I found a copy of the worksheet online and am interested in what score I come up with.