Pros
ARA has a strong engineering culture and generally tries to hire people who are passionate about the work. They also are very open to new market opportunities, and encourage individual initiative. Because the company primarily does "small" government contracts, there is a lot of chance at intra- and inter-company collaboration, which means you get to try new things.
Cons
It's a government contractor, so you generally can't work on anything that you can't get money for up front. You also have to deal with inordinate amounts of bureaucracy from "The Customer." "Everybody markets" is the slogan - and marketing is prioritized over engineering. If someone is bringing in new contracts, it doesn't matter how bad they are at engineering or teamwork.