We sent our kids through Montessori. Unfortunately, in the city where we lived when they were elementary school age, Montessori went through 4th grade before the kids had to go back to regular or religious schools. That was a rough transition.

But I still think that's a sucky situation for the 95% of kids who go to the nearest public school. Their days shouldn't be awful just because their parents didn't have the time, money, or awareness to consider non-default options.