The LImo, deluxe taxi, maybe more expensive than the regular car. However, it is more comfortable . Besides, a driver can speak english. Even though, it is not so well :D
For a long layover the sleeping options are great! The food options are lacking. Too many duty free stores that sell all the same things. Maybe turn one of them into a bar.
for incheon airport everything was good but immgation so bad a lot of people waiting around 2 hr for check, world best airport will good operation than u, will u see HKIA as case na
Flew in and out of Incheon from two different airlines and experienced 20-30 minute delays due to air traffic at Incheon. Something to consider if transferring to another flight
Free wifi. Easy to get in and out of this airport via subways or buses or KTX trains. Taxis to seoul or anywhere else is not really worth it and expensive.