Membership is open to any parent- With a PTO parents don't have to pay to join. PTOs are more inclusive and don't exclude people just because they don't pay to join. With a PTO membership is limited to parents and teachers (staff). One odd thing about the PTA is that anyone can join. So in theory an outside interest group could join a school PTA and take over. Should that be an option at our schools?
The parents and teachers can write their own bylaws, rules and policies with a PTO. They can customize the rules to meet the needs of their school. With a PTA the bylaws, rules and policies are written by the larger organization who may not know what is needed at the local level. They are totally out of touch and what one school needs may be totally different from what another school needs.
Take the great parents at a school + PTO = a well run parent organization