Pros
The world's most important organization for universal stability and peace. Surrounded by some of the brightest, well educated hard working human beings gathered in one place. Great place to engage and learn diversity with team members from all walks of life, background, nationality and race. Very clear vision from 1946 to implement and maintain human rights everywhere.
Cons
Huge unused HR potential with high potentials forced to think in small boxes rather than outside them. Management by fear of making mistakes or not to please reporting hierarchies. Micro management, ego centricity and self preservation frequently at the expense of creating motivating environment for improved team work and open exchange of ideas to shape the future of the UN.