Pros
If you are an engineer or scientist interested in National Security, this is your place. Employees are diverse and mutual respect is a strong part of the culture. You may have to work to find the right match for your skills, but once you are there the peer camaraderie and enjoyment of the work is bar none. There are a number of great problems to work on, and the mission space is diverse. The managers help to ensure that you have work to do matching your skills as projects ramp down/up. The safety culture is positive (even if a bit overbearing) and encourages us to talk about and prioritize safety; all work planning fundamentally includes safety planning. This is a process-driven place so one must have patience with that aspect, but in reality this protects you as well as quality of your output.
Cons
It can take some time to get into the department/work to fit your skills. Most of the company computing security rules are one-size-fits-all for non-technical users. For me, this is the single most frustrating part of my job. The number of people doing some tasks is not very deep, causing stress and over-worked employees in some cases. Procurement seems to have insufficient staff.