Pros
Diverse campus
Most faculty are very well-connected and supportive
Some opportunities for funded travel to conferences, etc.
I was able to get enough experience in 3 years as a TA to land a full-time job in the career field I want to pursue.
Cons
As a teaching assistant in my department (comparative literature), you will be mostly on your own if you are assigned to teach language course.
Grad students are notoriously exploited and this program/ position is typical of the field in this sense. The institution is a business at the end of the day, so remember that your health and overall wellbeing are not a priority for the university; as a teaching assistant, you MUST have strong boundaries or you will be burnt out by midterms.