Pros
It's generally a nice place to work. Many people are helpful and willing to share their knowledge. There are interesting roles to explore. I don't know how difficult it is to move about within the company though. Has done well in a competitive field recently. Hope that continues in this uncertain climate for foreign aid. Nice, quiet area and bldg has a lot of offices, so if you hate open plan and don't mind sharing offices, this would be a plus. Everyone gets an iPhone. Right on the Metro (though in a very expensive area). Good industry presentations. Work/life balance -- there is at least an attempt by most people to achieve this.
Cons
Benefits are not great. Only 15 days vacation for new hires. Only up to 19 after a decade. Considering the number of extra hours many people put in, this is not very good. Leadership is against people working at home or remotely. In this day and age, this is not a good way of attracting and retaining people. (Refer to fake review planted by management from late 2015.) Similarly, hates to close office even for a major blizzard. A few bad apples who bully and intimidate and need to be taken to task but are technically astute enough, and they're allowed to continue.