The greatest difference is surely the degree of Catholic practice of the bride and groom and their families. I have had couples who assist at Sunday Mass without fail as well as couples that I don't think had been to church since their first Holy Communion, and everything in between. It's much easier to plan and pray through a liturgy with folks who have been part of the praying community to one degree or another.
But there's another factor that makes a big difference. For whatever reason, we do a lot of weddings for cops, firefighters, and military personnel. There's something about these folks that makes them easy to work with; perhaps it's that they're used to rules and expectations. I say that I need such and such paperwork by this day, and it appears. I lay down rules about what may or may not be done in church, and they obey. It makes me think of the centurion with the sick slave in the gospels, whose words will soon be gloriously restored to the English translation of the Mass:
When he entered Capernaum, a centurion approached him and appealed to him, saying, "Lord, my servant is lying at home paralyzed, suffering dreadfully." He said to him, "I will come and cure him.The centurion said in reply, "Lord, I am not worthy to have you enter under my roof; only say the word and my servant will be healed.For I too am a person subject to authority, with soldiers subject to me. And I say to one, 'Go,' and he goes; and to another, 'Come here,' and he comes; and to my slave, 'Do this,' and he does it.When Jesus heard this, he was amazed and said to those following him, "Amen, I say to you, in no one in Israel have I found such faith. (Matthew 8:5-10)
It used to be that military service was considered a good preparation for religious life, though perhaps with the problems of decadence, New Ageism, and the general malaise in North American religious life this is less the case than it used to be. I'm thinking about all of this morning on the feast of St. Ignatius, who, like our holy father Francis, was a soldier before becoming a religious founder. For both of them, in different ways, their military service had a profound effect on the religious life they would inspire.
Ignatius, Francis, and all soldier-saints, pray for us.