I send my two boys to Catholic School. There are strict requirements for the parents in order to maintain a "participating" member status in the parish. I have to work Bingo every first friday of the month, we have to attend mass every weekend (you can only miss something like 6-8 times per year), and you have to sell raffles tickets for the festival etc...
The biggest difference that I notice is parental involvement. I can't honestly say that the education is infinitely better there is just more reinforcement at home I guess. We are seriously considering sending our kids to public school next year simply based on rising tuition costs. With the private sector being pretty tight about raises etc... tuition raises every year get harder and harder to absorb.