Pros
You have the opportunity to make an impact in the lives of children; the job is never boring; decent hourly pay rate.
Cons
Unreliable hours; during transitions between cases, the company will leave you stranded without any cases for weeks or months at a time (and therefore no income) even when you contact the scheduler and even HR to be assigned work; sometimes these periods of no work will happen with very little advance notice; in order to get assigned to cases, you have to hound the scheduler/poor communication within the company; you do not get paid when a client cancels, unless the client no-shows, in which case you can bill for 8 minutes of your time waiting at their doorstep (~$2). You can be a substitute on a case, but the behavior of the child you may end up substitute teaching is very unpredictable and therefore can be very stressful since you don't know the kid and vice versa. The kid may be aggressive or very difficult to manage, especially if you are not familiar with them.