Yes, obviously Miami is a much better choice. I would say from personal experience though, as of NOW, AA doesn't charge anything to change FF tickets, if there is another FF flight available for the same amount of miles later on. So you can book something you are not happy with, and then if FF tickets come up later on (even so late as a week or even a DAY before your flight) you can change with no fee. We changed our return flight from SXM in December a DAY before our return home for no charge.