Pros: Price and easy subway access (8-10 min walk from Sinimun Station-line 1). Clean. Towels changed daily. Easy check-in (let me check in an hour early). They seem to allow you to leave your luggage behind if needed (saw plenty in the lobby area). Small cafe on the first floor, but also has lots of nearby convenience stores, restaurants, and cafes nearby.
Cons: The room is very small, so not ideal for those with a lot of luggage (was not a problem for us). It was a bit hot in the winter, so you may have to ask to have the floor heating turned down in the room.
*It is kind of out of the way from most tourist sites BUT this should not be a deternt because the subway is so close by and easy to maneuver to all the sites!
Additional Info: The beds are somewhat firm which is standard for Korea, but some may not be used to it.