Pros
IMF is a brand name in economics. Like Coca-Cola to the beverage industry. As a Research Analyst (RA) you'll get a great opportunity to learn the ins and outs of country economics and data setups in Excel. You'll get to work with a good number of people and meet enough to build a decent network. You'll probably never get fired. It's 9-5 with every other Friday off. The salary is not bad r even good for junior people like RAs, although DC is expensive. Location is fine or good, depending on what you think of downtown DC. Looks good on a resume, and sounds good when you talk to someone at a bar in DC, but move to another city and no one will have ever heard of the IMF unless they have a background in policy, multilaterals, or economics/finance. Bosses were all very nice.
Cons
There are not many opportunities for advancement at the IMF if you are an RA. You can become an economist if you have a lot of experience, preferably also outside the Fund at a Central Bank or Treasury Department, but it is difficult to get this promotion unless you are seasoned and/or very very good at economics. RA jobs get a little repetitive after a while, since most of what you do is make charts and graphs, and download data, all day. If you are there long enough, you can start to get involved with research or things that economists do, but that didn't appeal too much to me. If you want to make more money, go to a bank but pay the price in hours, stress, and poor management.