And you get what you pay for. If you want to live in suburban hell in a house that looks exactly like the one next door, by all means look at the areas mentioned above. If you want a little diversity in housing types and neighbors, stay in Charlotte-Mecklenburg.
Myers Park High School (in Charlotte) is one of the top ten public high schools in the United States. It is ranked the best public high school in North Carolina (and happens to be located in the most beautiful neighborhood in the city in my opinion).
Union County is famous for low taxes and sprawling cookie-cutter McMansions. The town of Indian Trail has approved 9,000 additional housing units and they can't even handle the ones that have already been built. Union County schools are on a collision course with collapse due to rediculously low taxes. The County is imploding due to no money to expand roads, sewer and water, or parks.
If I was forced to live outside of Charlotte and had children, I would look at Ft Mill, SC in York County. Great parks, good schools, and even a decent suburban tract housing development called Baxter (new urbanist community with alleys, small yards, and front porches). Belmont, NC in Gaston County is a beautiful town very close to the airport with a great walkable downtown, a four-year Benedictine college (Belmont Abbey), and the area's only full-scale botanical garden (Daniel Stowe).