I had a one-night layover in Seoul, so chose to stay in Incheon to avoid the commute to the city. The hotel is about half an hour from the airport, so this worked pretty well.
The place itself appears very new, and the room was extremely nice -- lovely design and materials, all in top shape, very comfortable and clean. Really the nicest of the three I stayed in on my trip (including a pretty fancy one in Hong Kong) and absolutely nothing to ask for.
The area is okay too: lots of restaurants about, convenience stores, etc. There are also many many hotels in the area, though the neighbourhood was pretty empty during my visit -- there may be a draw there (beyond the airport) that I don't know about. They certainly have facilities for lots of visitors.
The only slight inconvenience was that airport busses don't come to the neighbourhood, but instead to a different cluster of hotels too far to walk. At £20 GBP taxi fare each way, it might make sense to book at one of those more expensive hotels -- but really a more pricey place wouldn't be more comfortable, and the neighbourhood might well prove less interesting.
All in all: a great place to stay!