Vantaggi
Great Mission, long history of working for children around the world, largest field presence among UN agencies. in many countries, UNICEF is THE "partner of choice" for children related programs and projects. Many highly committed staff who work really hard for the organization's mission.
Svantaggi
A huge bureaucratic beast - most of the processes and procedures haven't kept up with the changing landscape of time and development world. HR function is the worst. Slow, inefficient and HR posts are held by people who have been with organization for too long with waning motivation and interests in making thing s more efficient and helpful for people. Most managers are promoted from their technical positions who may or may not necessarily have ANY management skills or background. Poor management is rampant but interestingly, once you make it to manager level, especially to Representative or Deputy Representative level, you can't be fired. If a Rep messes up in one country, there's no consequence, s/he is just moved to another country, same Rep job... No accountability whatsoever. Technical staff, especially mid-level end up working like donkeys with little or no career development path. It's still a boys, medical doctor club in most offices. There's no mechanism to provide feedback. If you challenge management or disagree with the direction, there's no culture for healthy debate or discussion. Nobody wants to rock the boat and lose the job (they'll find a way to "abolish" your job if they don't like you) so people end up staying but miserable and nobody wins.