Pros
It's exciting to have the opportunity to contribute to something that matters: space exploration. It's a great feeling to know that your work contributes to the overall good of society rather than just chasing profits. In addition, I look forward to the time that my grandchildren read about JPL's successful projects in their history books and ask me what it was really like. JPL has a very friendly workforce. There are many kind and considerate people working here. The work environment is open enough that there are many opportunities to advance technical skills, as long as you're self-motivated to do so.
Cons
Compensation is not tied to performance, but is based on the idea of "salary management". Management is very concerned with keeping compensation somewhat competitive with what similar institutions are paying. However, there is not much consideration of financial reward for performance. Some IT technical decisions are based on organizational culture or politics rather than technical merit. While one technology may be a perfect fit for a project, another choice is often selected to avoid making some organizations or people unhappy. Promotions are based on who you know rather than what you've done. It takes forever to get things done. There is quite a bit of process control and bureaucracy in place here. Wading through the red tape makes even simple tasks very complex