Pros
Prestige and very interesting work. The opportunity to work on one-of-a-kind leading edge space missions is great. The people are extremely intelligent and capable.
Cons
Management at JPL is below average. The Lab does not realize that management is something that can and should be taught. Furthermore, good engineers do not necessarily make good managers. There is too much time spent on trying out managers and having the bulk of them fail forcing them into dead end jobs as burden-suckers. It would be better if one had a systematic approach to identifying management material and training them to do it right instead of winging it. JPL is not motivated to find low cost solutions. As a result, the costs of missions spiral out of control. JPL should investigate ways to reduce costs and reward engineers for saving money.