Sejong inn has very accommodating staff. Less than 5 minutes walk from Myeongdong station and airport bus stop. Breakfast is good (toast, cereal, fruits, coffee, milk, juice). The rooms were exactly the same with the pictures shown here. Fast WiFi.
I stayed here for 5 nights total. I went to Jeju island between my stay and they agreed to store my luggage for free during the 3 days I was not checked-in.