The room is clean and comfortable, despite its size. It's really nice to have an opportunity to do the laundry, cook meals and have a cup of coffee. A bit of a challenge to sort waste by yourself at first, but you'll get used to it.
The bathroom is right in the room, but has a good ventilation and doesn't smell.
The soundproofing of the rooms isn't good, but I didn't have any problems with it. Flickering neon lights from the street can be a problem for people that can fall asleep only in a completely dark room.
Overall a really good quality/price ratio for a comfortable room with your own bathroom in the center of Seoul.
I have a few suggestions: although neon lights in the night weren't a problem for me, but can cause difficulties to fall asleep for other people - it would be nice to have blackout curtains.
Also it would be nice to have hair conditioner in the room - the shampoo dried out my hair badly and I didn't have my own hair conditioner with me, so I had to buy one.