It's unfortunate that the merit of computer and television use by 5-12 yr olds is wrapped up with the Waldorf schools. A broken clock is right twice a day and limiting kids' exposure to computers and TV (screens in our household) is the two times Waldorf gets it right.
If you want to raise your kids to be intellectuals relative to their peers, all you have to do is ban screen time in your household and provide plenty of engaging books and spend time reading to your kids.
As for schools and quality, all I really see are generally high quality schools in Minnesota. Both public and private. The difference is almost 100% in the home, but criticising parenting is not in vogue, so we do not discuss this publicly.