Pros
This is where you want to be if you're background or career goals is to work in economic development, public policy making, M&E, etc. Benefits and salary are huge if you are hired as an international employee to work for a country office (you can only be hire as a local in your home country). The action used to be in HQ, however, nowadays, with the decentralization process, the hands-on and, in my opinion, more exciting work is in the Country Offices. They are the ones getting all the face time with government authorities and executing agencies, and a executing the projects from a first person stand point of view. It is a very international and friendly environment. Long and fun lunch hours with your coworkers are usual. You get to meet people from all latin america. Most economists here are all PHDs from big name universities.
Cons
This is not the place to work in a support department (Legal, HR, IT, etc.). Many of these functions have been outsourced, their budgets reduced and thus their headcount reduced. This of course is natural since the Bank's business is not to do HR or IT. If you do join the Bank to work in one of these functions, you will find that it is completely outdated compared to other organizations. It is a very bureaucratic organization. Changes are slow and there's always a lot of resistance. Once you become permanent staff, most people will very likely aim at retiring from the Bank because of its attractive pension (which is no longer the same for new employees since a few months ago). However, because of this you will find many who are outdated and don't put a big effort into their work. If you've worked for a public government in Latin America, it is basically the same but all nationalities in one single place. If you don't speak spanish, you will probably have a hard time even in HQ.