Pros
1) R&R every three months + stipend. 2) Get to interact with an international community, including locals (Although not as diverse as it should be. There's clearly a bias against foreign applicants that are not European or from the U.S. - this also applies to career mobility).
Cons
I don't even know where to start. Here goes a loooooong list that will probably take you more than a couple of minutes (please really digest it): 1- No meritocracy. If you are friends with high-level executives, then chances are you will receive a higher-level position. It doesn't matter whether you have experience or not. Chances are you will have more experience and knowledge than your senior managers. (This is surprising and certainly makes you raise an eyebrow as this is atypical for an international organization). 2- Research is being carried out by people who do not know how to do quantitative or qualitative research so it should technically be invalid. The methodology is not even an existing methodology. It is made up and does not follow quantitative or qualitative standards. 3- There are no security and safety measures besides the onboarding induction session (which is not adapted to your base location). You'll most likely have to ask UN to include you in their very detailed, top-notch induction. If nothing has happened to anyone so far, it is just out of pure luck. 4- A lot of manual work as nothing is automated or standardized (which takes a loooooot of time. This considering that in a humanitarian setting everything should move faster). 5- Security managers have no previous security experience. Most likely are bartenders. 6- Guesthouses are old and dirty, infested with rats and cockroaches, and have a foul smell all the time. Bedsheets are NEVER washed. 7- If you are field-based then logistical arrangements will fall on you (you'll have to look for a place yourself unless they have an ACTED GH on the field location or they allow you to stay at the UN compound). 8- Besides leaving the logistics up to you in unsafe environments (esp. problematic for girls), there are no follow-ups regarding your whereabouts, don't expect anyone to carry out an inspection of the place where you'll be staying, no safety measures installed, etc. Again, if nothing has happened to anyone so far, it is just out of pure luck. 9- Underpaid for the work you do. R&R does not suffice. 10- Bias against foreign applicants that are not European or from the U.S. in terms of career mobility but also recruitment. 11- It's 100% true what they say in the comments below (my bad for not taking them seriously before accepting the offer) - when you raise alarms about something that's not working in the organization, they will find a way to kick you out as punishment for not keeping silent. 12- HR management clearly has no experience or training in HR management, besides having an uncivil attitude. 13- Offensive, discriminatory treatment with local staff, which should be unacceptable, especially for a so-called "humanitarian organization". 14- Monotonous work (most likely, you'll be doing spreadsheet cleaning and copy-pasting information into a factsheet, published two months too late, daily). 15- If you were kicked out of the organization for not putting up with how things unfairly work, they'll blacklist you for the rest of your life (e.g. if you apply again, they will not even be cordial enough to send you a reply regarding the status of your application). Basic courtesy. . . . And the list goes on... If you are a serious professional, PLEASE PLEASE read the reviews (esp. the low reviews) and trust everything they say. THEY ARE ALL TRUE. Don't expect to join the organization and god willing something bad happens to you, then you will regret having had this experience for the rest of your life (plus, it will ruin your CV). After I left, colleagues from my mission and other missions started leaving by the dozens as well, related to the reasons I mention above. This all is deeply concerning, and unacceptable for a humanitarian organization.