Pros
We work on stuff that will end up in every 5th graders science book. 95% of the people that work here love their job, and are willing to help you out. Good team environment. It is really refreshing to work with intelligent people.
Cons
It's government, so new ideas from a process perspective are slow to implement. However it is a "Science" government agency, so new ideas from a technology standpoint are welcome (if you present the idea in using the correct government "process"). I work KSC, the engineering - rocket launching side of NASA. Sometimes work is a "hurry-up and wait" environment. The average age out here is much higher than industry, so I'd say 5-10% of the workforce needs to retire and let the younger generation take leadership roles.