Ventajas
You gain pretty decent experience with working in a classroom setting, as well as practice in teaching students individually. The work isn't very hard and can be quite rewarding.
Desventajas
The management is the most unprofessional group of college students I've ever worked with. Management is more worried about you standing at one designated spot for breaks/lunches than providing quality instruction from within the classroom. They underpay you by giving you a "stipend" that equates to less than minimum wage. I mostly blame their hiring process -- there are definitely a good 20% of TAs who are not professional at all and try to get away with ditching work or coming in late. As a result, management looks down on the rest of the TAs who are trying extremely hard. I've worked here for two summers, and I can say that this TAing position felt more like a babysitting position.