Pros
You get to do important, morally good work. The company has a grand vision greater than making money. It is a truly global company that has a world view instead of a US centric view. The employees are great and very diverse with a good overall variety of races, religions, and many women work here.
Cons
The computer systems and testing framework is incredibly slow which can be frustrating when developing code. However, they are always working on this issue and have made improvements. They also, like all companies, need to create more democratic system and try to dismantle the hierarchical system of management. However, I recognize most companies this size are fairly fascist. Navteq actually makes sure that the processes are changed, updated, and work for you.