Vantaggi
You will lobby your congressional delegation, you will be on TV, you will get to voice (some of) your views and meet lots of passionate people across the country and in your state. You will also go on an awesome vacation nearly entirely paid for for a week in the winter. Some of the coworkers you meet (mostly canvassers) will be amazing people.
Svantaggi
Ultimately, most fellows don't last for two years or go on to work in the network because there are too many factors making the job unsustainable, even if you're really into it. In a seminar on why the everyone quits, they did a survey. Pay and hours were at the top. You will starting around 24,000 a year for working 50 hrs a week or 80 during the summer as a canvass director. That's fine if you have parents paying your rent, or you enjoy spending 95% of your waking time in the office and enjoy the people you're working with. However, if you're a 20-something with no one supporting you monetarily but yourself it will be difficult to make ends meet. Environment America is about 98% white, and from what I could tell, most people were upper middle to upper class, which makes sense when you consider the pay. The network prides its self on doing things inexpensively, which is great, however, I don't think that should negate paying their employees decently. Getting paid enough to be able to afford car insurance, for example, shouldn't be considered excessive.