Copa goes to Panama, there is usually a short layover "in-transit" -maximum of 8 hours is their rule (i.e. a dominicano doesn't need a Panama visa, but may not exit the airport lounge area, which is full of shops and restaurants, etc) and then on to anywhere in Central or South America.
Really easy, beautiful new airport, and NO HASSLES. I have permanently QUIT Miami for my travels because I can get where I need to go through Panama, including Los Angeles.