All 3 of my kids are gifted. Our elementary school was very good at teaching kids at their level. All kinds of accommodations were made to make sure they were challenged. At the Middle School level, I was met with resistance and hostility. My oldest son was the guinea pig, unfortunately. He was bored throughout his middle school years, keeping himself challenged with Spelling Bee, Geo Bee, community service, home projects.
Middle son was lucky and had a strong peer group who raised the whole class's level some, so he survived.
Youngest (daughter) is being homeschooled for Middle School, because there was no accommodation and no strong peer group for her.
Our school DOES allow partial homeschooling, so I take her for Science and lunch. Just enough that she can swim for the school team and keep up w/ her friends.
At home I use online gifted classes through JHU's CTY and am very happy w/ them.
I would caution you against pulling your child out too early-I think an important function of school is learning that not all the world is just like your home. What my kids learned at school is how to get along with all kinds of people. Also, I was able to raise my school's awareness of the needs of gifted kids, since not all gifted kids have gifted parents who know what to do w/ them.
I did not take my kids out of public school easily. What I tell people is that I "Homeschool AND send my kids to school." Most of the real hard learning they have had at home, but the lessons they learn at school are also valuable.
Good luck!