By "free" I assume you mean tax-payer-paid public school?
We had our son in public school for one month in Kindergarten. It was apparent when the school placed him in the third grade classroom for reading that it wouldn't work. Not because our DS (five at the time) couldn't follow the reading, but because the teacher required a book report of him. His handwriting skills at the time couldn't have kept up with that.
Now we have him in the public charter in our district. That's also free, but the school only receives 60% of the funds normally afforded to a student, so there's a lot of fundraising to make up the deficit. I'm personally okay with that because I think it teaches community involvement, but I know a lot of parents don't have time/don't want to make time for that.
There's plenty of information on this board about advocating for your child within your own school district and the results all vary. Sometimes it depends upon how "gifted-friendly" your state is, and sometimes it doesn't make a bit of difference. Especially when you butt heads with a particular teacher and his/her preconceived opinions.
