Pros
Fantastics grounds. The main campus of the lab covers several hundred acres and the entirety of the laboratory covers 5300 acres. Retirement contributions are currently at 9% of your annual salary vested within five years. If you are salaried, I believe you start with three weeks vacation. There is ample sick leave, a onsite cafeteria, post office, picnic areas, tennis/squash courts as well as a gym (annual fee for gym) among other facilities. The laboratory pays up to 75% tuition on Bachelor's Degrees and 100% on Masters Degrees (must be related to onsite work. This covers a wide variety of fields). There are also numerous clubs covering a variety of topics. People often meet thier spouses during thier work. Thier children end up working at the lab.
Cons
Take home salary can be smaller than the outside world. There is a lot of bureaucracy. Tasks that would ordinarily take a few days in the corporate world can drag on several weeks, particularly in the IT departments. This is partly because the lab isn't profit driven. If you are an IT and early in your career, raises and promotions aren't competitive with the outside world practice of switching companies every few years. However, your benefits cannot be beat by your typical corporation.