Vantaggi
The most important fact -- The work is important and exciting. Of course that's offset by some drudgery and bureaucracy, but the big picture of spaceflight objectives keeps most people pretty well motivated. Because of that, NASA routinely makes the top of the lists of the best places to work in Government. They do try pretty hard to take care of their people, within the limits of Gov't regulations. Lots of non-monetary awards, "company" picnics and events, etc. Mostly outstanding staff (engineers, first-line supervisors) and a pleasure to work with most co-workers. High technology. Ordinary people doing extraordinary things.
Svantaggi
Salary/Compensation isn't as good as private industry. Bureaucracy is rampant. While my experience showed that MSFC could be adequate technology risk-takers, their culture is extremely bureaucracy-risk-averse. If HQ tell them to do something stupid, they will be very good soldiers. Maybe comes from historic Army background. Also infrastructure (CIO, CFO) organizations run roughshod over the mission organizations. If we don't make it back to the moon, that will be why. Can be frustrating at times. I saw another reviewer complain about no job promotions because of "dead wood". I didn't find that the case for my career. The parallel ladder is a problem in every organization, gov't or private. MSFC didn't seem to me to be any worse than other organizations.