As you might expect, NASA is full of bright and creative people, and these are the types of people that are easy to work with and get along with. Lots of opportunity to move to different projects if you so desire.
If you are a researcher it's a great place to be. The department cares about you and even if your projects is completed or terminated your get reassigned to new ones. There is also a lot of intellectual freedom. Flexible time and vacation.
Cons
The technologies used are not necessarily the latest ones. You should be careful to choose a position that will keep you revelevant in the private sector as well.