Pros
Great work life balance. Management was very supportive, helped me whenever I needed anything. Everyone there was friendly and relatively easy to work with. It was generally a low pressure environment; if you were smart and didn't surf the internet all day you would do fine. Also the salary was pretty good for me, since I was only a few years out of college.
Cons
Very bureaucratic, they reward loyalty much more than performance. Your best (or really only) opportunity to move into upper management was if your manager got promoted or left. Some people were able to transfer to other groups, but that's the rule rather than the exception. The work itself was relatively boring. You enforce esoteric rules and write pretty boring memos. Most of the smartest people ended up leaving after a year or two to do something more interesting.