I worked at C2 in 2008-2009, and I'm glad to be back.
Pros
I love my coworkers! Everyone at HQ has a really cynical sense of humor, which makes the workload much more bearable. Really great support amongst coworkers. Grading essays from students, while mostly tedious, can also be a bit fun whenever you come across one that stands out. The first time I worked here, curriculum development was boring, but they're working on a lot of new content that's actually fun (or at least not boring) to work on. The pay is also the highest I've ever had at a part-time job. And there's always something to do, which I like very much!
Cons
The higher ups do expect an awful lot of you, which is usually motivating but can often be frustrating. They seem to have no idea of how long it should reasonably take to do something. When I graded essays a few years ago, center directors would often send essays that they wanted graded immediately, even though our usual turnaround time was 2 days. But hey, at least I learned how to grade a 2-page paper in under a minute!