Pros
Stable with good health benefits, to be specific. Monetary compensation itself is *very* average; would even as far say it's quite low for an intergovernmental organisation and the workload you're given under this "regime". Generally speaking, I would say the pros and cons depend on what you're looking for in a career. If you're looking to work a stable, boring 9-5, this would be the job for you.
Cons
No overtime pay, yet you're *always* expected to work overtime. No work-life balance. No 360 review - it's top down. Extremely bureaucratic and no career progression whatsoever- you can become a Senior Officer from an Officer and so on, but you would have to apply for it an compete with external candidates who might as well know much less about the job than you. There's no promotion. Some people retire as "Officers" but if you don't mind that then it's not a con.