The experience of a research fellow/consultant depends a lot on which researcher you are assigned to, so make sure you know that their interests and style align with yours - some fellows get assigned very interesting projects and have lots of work; others get assigned boring projects and/or don't get assigned much work. Try to get a sense of what projects you'll be assigned before accepting an offer.
I thought future employers would be more impressed by my experience at the IDB. So far, it doesn't seem like they care that much. The experience is a very good stepping stone for a PhD program, but probably not so much for doing other things.
Some fellows or consultants get hired back after their contracts expire, but it's depends on how you look at it if this is a really desirable situation or no. If you don't mind working contract to contract and that instability, then there's no problem.
Is not a "con" exactly, but something to know - Base pay for a fellow is around $65,000 / year, then you get an extra approx. $450 for "savings plan" and $250 for health insurance. Your final pay depends on two things - 1.) Are you married or single - if you're married, you get an extra $500/month for health insurance (or $750 total). 2.) Are you American or other nationality - Americans pay taxes, other nationalities avoid paying taxes to the U.S. or their home countries. Americans also pay higher taxes than they would at another employer, because IDB doesn't pay social security taxes.
