Ventajas
Good way for students to get to know teachers better outside the classroom. This really helps if you need a recommendation for graduate school or a job. Good insight into the workings of higher education for those who are interested in pursuing a career in university teaching/administration.
Desventajas
I was by far the most organized person there. A lot of my work involved wading through the layers of bureaucracy just to get simple things done, like copies of class materials. I think that people's experience depends on the professor they are working for. In my case the prof. was a great guy and easy to work for, but in interacting with the other people in administration I found that there is a frustrating amount waste. While there are some very helpful and nice people working at Rutgers, I thought that far too many were lazy, and they often acted like they were doing me a favor by simply doing their jobs.