Incheon International Airport (IIA) is so clean, and so systematized. I can’t really provide a comparison from other international airports since it’s only my first time overseas. I traveled alone on interconnecting flights from Cebu-Mactan International Airport to Kalibo International Airport then directing a 4-5 hour flight to Incheon International Airport. Am fortunate to experience traveling alone domestically, but not overseas.
One of the unmentioned features of Incheon International Airport would probably be the train. Upon arrival at the Airport, you have to ride a train going to the other side where the immigration and exit gates are. Some Koreans noticed me and merely assisted me also, since I’m neither in a Vietnamese, Chinese nor Caucasian group for the matter, but simply alone.