Why retire in Latin America
There is an article in the Christian Science Monitor titled Why US baby boomers are retiring in Latin America that is rather good. If you already moved and are happy with your decision, you probably don't need to read it. On the other hand, if you need a bit of a kick in the rear or need something to explain to your friends back home why you moved, it is a pretty decent starting point.
Rather than the typical piece written by someone with something to sell, the article has multiple authors who at least don't appear to be trying to sell you anything. (The exception are some quotes from those who would like to sell you something but they are only about the idea of moving.) It covers both the up-side and the down-side of various locations.
Retiring outside the US certainly isn't everyone's idea of utopia. One of the biggest obstacles is a simple one: managing expectations. Some people think living in Ecuador, Panama, or Mexico will be the same as living in the US, only cheaper. It isn't.
As Zach notes, many countries in the region operate at a different rhythm. A less-frenetic pace can be good for retirees. But it can also mean slower service at a restaurant, notorious bureaucratic delays in getting land titles or driver's licenses, and scheduled dates with plumbers or carpenters that never happen.