Originally Posted by
corbomite
The only hotel near the airport of a similar caliber is the Grand Hyatt Incheon and since the CALT is right next door, it's not worth moving. Get to the CALT 4 hours earlier, check-in, go through immigration, and then when you get to ICN, you can use the fast track.
The only potential problem would be traffic jams on the expressway on the way to the airport.
I've been in some bad traffic jams in heavy rain when leaving from ICN. I prefer to spend the night at the GH ICN, although it can be expensive for what it is. I like the fact that the hotel's airport shuttle runs about four times per hour. (There's also a free public airport bus alternative, mainly for airport and airline employees, that stops at the corner of the hotel.)
Some additional hotels have recently opened near ICN. However, be aware that Incheon village is far from the airport. Travel time from some of these "airport hotels" can be no better than from most of Seoul itself.
If you want to spend the last night downtown, consider a hotel where you can walk to the main train station and go to the airport that way, thereby avoiding concerns about traffic jams on the highway.