I speak to many couples who tell me that they have a friend or a relative who is going to get a one day license to perform their marriage. Do you really want to take a chance on an unprepared friend or family member who has never performed a Wedding?
Marrying a couple requires training. Is your Wedding the right place to let Aunt Martha practice to be a Wedding Officiant?
I hear horror stories of entire parts of ceremonies being skipped or performed incorrectly, using friends or relatives. If your friend or relative is a professional Officiant, then having them perform your Vows is an awesome idea.