I think this hotel would be okay for short stays, but I wasn't thrilled with it for my 2.5 week trip. The area is magnificent and the staff were all kind and helpful, but I had some minor issues with many aspects of the property itself. The room was quite small and not adequately ventilated, so it became overwhelmingly hot and humid while you were away (and the bathroom never dries fully). The expedia listing mentioned a washer/dryer which was the main reason I booked here, but those were not available for customer use. You can ask the room to be "made up" any day you want, but I quickly discovered they did not clean the rooms or even replace the bedding. Only towels were refreshed and sheets were put back properly on the bed... but not cleaned. Due to the humidity of the room and my longer stay, this was really unfortunate. Finally, these rooms are absolutely NOT soundproof... although it was mostly quiet and not an issue, there were several times I woke up to a dog barking in another room or someone throwing up. Unfortunately, that second one happened multiple days in a row, but I guess Hongdae is an all night party area, so it is what it is.
Overall, I don't think I'd book here again unless it was a short stay (maybe 2 or 3 days at most). For a similar price, you can find much higher quality places around Seoul.