Pros
The people are great and friendly. It's the best place to be in terms of government contracting. The work is interesting, proposals are well done, and the time to finish project is pretty flexible. Also, the flexibility given to daily life is pretty good; work at home has been a viable option depending on the team and project, and even though the work is very project-orientated, the team understands personal commitments and need for time off, such as appointments, travel, health, etc. For working mothers, it is very good; there is a day-care center on-site, and adequate maternity leave is given.
Cons
When it's proposal season, the hours are pretty long and rough. It's made up for by the hours during the other times of the year being pretty good and allowing for anytime to have a personal, home life. So work/life balance during most of the year is fine, but watch out for proposals. Also, since background clearances are presumably expensive, it requires a bit of maneuvering to try to get one in order to be eligible for more projects, but unless someone at a higher level than you helps you get one, it is pretty hard. Also, there is the "bulge" at the level 3 (associate) that's hard to break out of.