Going abroad is probably of more value to you yourself, than it is when it comes time to application. I went abroad once for educational purposes and took classes, and once to do some volunteering. I got totally different things out of each experience. The first one was more to learn the language (Spanish). I stayed with a Spanish family who spoke NO English, so that really made me use my skills. The second opportunity I went to Argentina and volunteered in a public hospital. This opportunity is a huge reason why I want to worked the underserved in this country. It has given me a lot to talk about in my secondary applications, and obviously the more exposure you have to medicine the better in terms of the application process, but I don't think the edge up is as big as you are thinking it is. I would say do whatever program you are most interested in versus what will look better on an application. Going abroad is an amazing experience, and the more you learn from it, and the more you have fun, the more passionate you can be when talking about it. Also, going abroad to take classes doesn't mean you can't do any type of volunteer work while you are there. I took a medical Spanish class while volunteering in Argentina...maybe something like that would benefit you? Kind've the best of both worlds...