- Excellent customer service is one of the best features of the United Airlines MIA Terminal. The airline employees are kind, professional, and always ready to assist travelers with their issues. The United Airlines agents make sure that everything runs smoothly, whether it's baggage questions, flight adjustments, or check-in assistance. The gate agents ensure that planes depart on time by managing boarding operations efficiently. The terminal employees are also well-informed and offer straightforward instructions for getting about the airport. United Airlines is a dependable option for passengers flying via Miami International Airport because of its excellent customer service, which represents the airline's dedication to client happiness.