Pros
Unlike private tutoring, working for C2 means that you don't have to find your own clients - the center director does that for you. You get relatively stable work with some seasonal fluctuation (summer, for ex., tends to be busier). Most of the kids are really nice and make it worth it to come in every day. Senior management (at the nationwide level) is fantastic. One of the co founders (Jim) will often come around to centers on the west coast to chat with the teachers and give advice. He remembers teachers' names and is an extremely nice and down-to-earth guy.
Cons
This might be a center-specific issue, but the center management is terrible. The director is far more concerned about catering to clients than about teacher needs, and often makes unreasonable demands on teacher time. It is extremely difficult to get a raise, and it feels as if sick days are not allowed. Scheduling can be erratic and change at the last minute. Schedules are sent out the night before, so it's hard to make plans for the future. Saturdays are fairly busy, which means that you don't get a normal weekend. Typically, teachers have Friday-Sunday off. No benefits and no paid sick days. Weekday scheduling is 3 classes in a row, which means you work 6 hours with no break.