My children attend private school (Hacienda School) and it is difficult to know academically where they stand in comparison to public schools. There are no report cards but instead very in-depth reviews. The great part is that the kids can focus in on the subject matter and not worry about grades. The other thing I really like is the small class size you get at a private school. The learning is very individualized and for middle schoolers especially, the kids can focus on academics instead of the peer distractions that come with the pre-teen years.
Our school is year round and full day so I do not have to make arrangements to cover after school care and all the non-school days associated with attending public schools. This also means no homework. The end of the day is family time. We also have the luxury to take vacation any time of the year that fits my and my husband's work schedules.
The other part I like is that the tuition covers everything. I have heard in public schools that as a parent you have to continually open your check-book for special projects, school supplies and fund raisers. So in the end neither is free.
Even though we chose a private school for our kids, we are very thank full for the high STAR scores here in Pleasanton as it has kept our home value from declining very far during this recession.