Pros
The money is outrageous for the effort and skill required, especially at lower staff levels. I never worked at a place were my net salary actually turned out higher than my gross salary (thx to the manifold of allowances and per diem extra's). You can live like a king among the locals who are taxed to death and therefore lack the necessary purchasing power to compete for the best houses, restaurants,...
Cons
Entry (even through the so-called "ardeous" concours) is mainly based on politics (ie filling up informal nationality quota or handing out jobs to friends, nephews and political allies). Promotion is based on all of the above as well. Things take tiiiiiiiime and every-one is slooooooow. People are eternally wary of one another and covering one's arse is a full-time obsession. People are used to complaining, but firmly remain in the gilded cage. Further, I found there was a very condescending attitude towards local residents who are generally looked upon as a breed of primitive serfs. In the end I was glad the private sector would have me back.