Hi Jocelyn! Good question! To be honest, there won't be a huge difference between on campus or off campus jobs assuming you are working part time. I did work study all four years of college in my campus dining hall. This job I started off like any other where I made minimum wage. Each year my salary was increased and I would sometimes receive bonuses. From my experience this was consistent with the outside job I had in high school. The only difference I could foresee is if you got a job where you would receive tips. Work-study jobs won't give you any tips so it would only be your weekly salary.
The pro to work-study jobs is that they understand that you are a student first and might be able to be more flexible when school conflicts arise. Also, my campus job helped me to quickly make friends at school and feel a part of the campus which you might not get at an off-campus job.
Hope this helps!