Mediation is a great thing and it makes a tremendous amount of sense as the preferred resolution mechanism in family matters. In most cases the 'best mediator' may just be a friend offering common sense advice. But the key point to real success, is two EQUAL parties and not a FORCED agreement.
Right now legislated mediation does not work as well as it should because of those two principles. Many people are surprised that we would say the 'default' living arrangement should be alternating weeks with both parents -- period. No special rules for vacations, birthdays, age, etc.... This may not result in a starting schedule that some might consider 'best' for the child and parents -- but it is up to them.
Once there is no power struggle the parent's can then work it out between themselves or turn to mediation for help. It would be much more effective.