Pros
Very good place to start your career. There isn't much assistant-type work to do, so you're given the opportunity to work learn very quickly. You can work on books from other disciplines, giving you varied knowledge, both about subject matter and about how different people work. And no matter what department you work in, you get exposure to working with almost all other departments.
Cons
This is not a place to grow. Pay increases were not great, nor was there much difference between being an assistant and an editor. Once you master your position, it's best to move on. Also, your employee experience is almost entirely dependent upon who your direct supervisor and manager are. Also, be aware that this company is not located in Boston, and a car is required to get to work.