Debbie, I am going to repeat my mantra - when you accelerate your kids they are not going to be in a class of smarter student, they will only be in a class of older students.
My DS (sorry for repeating myself) was placed in Algebra 1 for his 5th grade. He was taking that class with a few 6th graders, but majority of kids were in grade 8th. He was still getting A and was the only one in the class being able to answer challenge problems. Was he being challenged? Yes, he was challenged to learn more but I do not think that this is necessarily the way to go. When you have time, read this http://www.artofproblemsolving.com/Resources/AoPS_R_A_Calculus.php
I have always known intuitively that going faster and faster is not as good as going deeper. But what can you do if the system is only offering faster? I am thankful for that and am supplementing at home with challenging problems.
It is much easier to challenge and supplement at home a kid who is in elementary school. In middle and high school things become way more structured, there is more to do, even in regular easy classes, there is just less time.
Our son has already fallen into calculus trap. He will be done with pre calc when graduating from 8th grade and ready to take AP Calculus BC in 9th grade. Is it good for him? - of course not. But there is nothing better being offerd at this time.
He earns As accross the board. It is absolutely not relevant to his learning.
I am really exhausted in spending so much energy on educating my kids - just making sure thay learn according to their ability. I had much more wind beneath my wings when they were younger, thinking that by improving things for my kids I will also improve things for others. But it is so difficult to change anything, and time goes by so fast, that by the time any changes are put into the system it is more often than not too late for your own kids to take advantage of it.
But probably the most frustrating thing about it is that most of the time I feel like the only crusader (not on this board of course :-), like other parents do not get that in order to learn you need to be challenged.