Hello! My experience at Frontier Airlines MIA Terminal was smooth in general. The check-in was a snap, although the lines did get long at times. The personnel were courteous but obviously in a hurry. Security flowed well, and the terminal was clean but very crowded. There weren't a lot of food sources around, so eat before arriving. Boarding proceeded according to schedule, and the gate area was well-organized. Not fancy, but it did the trick. If you're flying Frontier from Airlines, get there early, be patient, and you'll be set. Budget carrier, budget mind. No huge complaints—keep it simple.