Pros
SSA provides job security and opportunities for different experiences through rotations, career development programs, and short-term details. Also, the positions are graded higher when compared with similar positions in other agencies.
Cons
The work is so esoteric that I don't see you gaining lots of transferable skills from working there. It is almost like if you remain at Social Security too long, you are forced to become a lifer! Also, people there shuffle around in so many areas that it is hard to concentrate in a targeted career area. For example, people become managers in HR who don't have an HR background. Depending on where you work, there is a very traditional mentality that in order for you to move up, you have to have field operations experience.