Pros
Goldstein Test Prep allowed me to gain some teaching experience, earn an income while having an irregular schedule, and apply skills that I've learned as an academic. I graduated from the University of Pittsburgh in December and was "docked" in Pittsburgh while I was waiting to go to graduate school in the Fall. This meant that I had an "awkward" window of availability in Pittsburgh, on top of an irregular schedule due to travel for graduate school visits.
Because the appointments are self-set, I was still able to work through Goldstein Test Prep while also holding part-time research and teaching positions at the University during the day-time. Furthermore, although I worked as a temporary part-time employee, I was able to use my background in mathematics and writing that I've developed through my education - this was a much more fulfilling position than simply working in retail or at a restaurant.
Cons
You will likely need a car for this job, and some of the appointments can be far (20-40 minutes away). If you are a student and you are involved in many extra-curricular organizations, it may be difficult to balance your time with the tutoring appointments since they occur in the afternoon/evenings of the week, and you will need to be away from campus at the times when many university organizations tend to meet.
Fortunately, Mike (the boss) is pretty understanding and willing to work with you by trying to organize nearby appointments with each other so you can minimize driving time. Also, if you need to limit your hours based on your university activities, Mike will work with you to re-organize your tutoring schedule.