I recommend this out-of-Seoul-city Hotel -if location suits you. I recommend some snobbish Paris Novotel staff to have a trip here as well, to understand what Customer Service is.
Clean, good food with a lot of options, very good Spa with big pool (25m?), gym, barber, cobbler etc.
I had this time some communication issues: I hadn't swimming suite and they invited me twice to go to the mall next door to buy one -later i found you can loan for free in the spa area, all clean and in different sizes. I said that I wanted to go to the barber: they said it closed at 2200, but when I called around 20:00 I was told it closes at 1930. I always spoke with different people and my impression is that no bad will, just understainding difficulties were the problem.
Overall I was pleased by the service and I will definitely come back here next year.
You will be satisfied, just make sure you and the staff understand each other well.

It is not the best Novotel I have been, as it looks a bit old, but the price is good even at Executive floor. A good point is that the 6004 airport bus stops in front, and there is a Home Plus shopping mall across the street.
Internet was (as usual in Korea) very fast and free.

friendly staff, clean room, good breakfast.
good facilities provided.
resturants, supermarket & convenient stores nearby.
15~20 mins walk to subway station plus 30 mins to city centre.
easy to get to airport via airport bus.

I'm using for my family trip. Because this hotel is very favorable for the children.
My children can using the lounge and swimmimg pool without any restriction.
It is very good point for seleting the hotel for family trip.
So, I will revisit this hotel in near future.