Vantaggi
If you want experience, this will give it to you. You can teach all levels pre-school to college. You'll get experience working with different students at the same time and working with special needs students.
Svantaggi
Though it gives great experience, it's really not the best for children and their families. I am a private math tutor now, and that is the way to go; they will often pit you with a very distractible child doing basic reading (who really doesn't want to be there and wants to goof off), a middle school student with math homework, and an ACT student who really wants to learn. Your priorities as a teacher at Sylvan isn't to give everyone there money's worth (which the rate is around $45 an hour per student!) but baby-sitting and making sure your table behaves and is quiet. They didn't care how much I taught them, just how much I kept the noise at bay (which can be extremely difficult), and those poor students who really wanted something out of it really waste their time and money because I can't focus on any one student, and those loud students will definitely start to take high priority or else teachers and the directors will complain to you.