Amigos is a great experience for high school and college students alike. I participated in the program this past summer and had an amazing experience. You are placed in a community, generally rural (although the DR is the most urban country in the program, I believe) with one or two other partners. You live with a host family, lead activities with children, and collaborate with your community on a project.
The best part about Amigos is that you're on your own. Yes, you have a host family, and yes you have a partner or two and a supervisor, but you are the one who makes sure you finish what you need to. You're in control of your own experiences, and while there is a great staff and support system, it all comes down to how much you want to get out of it.
On top of that, Amigos is affordable, especially in a chapter where you fundraise together. I was given a scholarship through my chapter due to my family's low income, bringing the price down to about as much as the flight would cost.
The Dominican Republic is a great place to go with Amigos. The people are friendly, they're willing to help, and the music is non-stop. While the dialect is difficult to understand, you get it eventually. The climate is hot and humid, but the rain cools it down.