We stayed at Kevin's apartment in Yongsan area for a month. Kevin and Bill were both very available through the booking process and answering any questions we had. Once we reached Seoul, the check in process was super smooth. Kevin was coincidentally in Korea when we checked in and he welcomed us and gave us all the information we needed.
The apartment itself is very modern and comfortable. It has all the main amenities and it is also very conveniently located within walking distance to 3 subway lines. The apartment is very secure and clean. The unit was stocked with lots of towels and having the extra half bathroom made it very convenient to share the space.
The apartment is ideally situated and at most a 15 min subway ride to a lot of main areas of Seoul (like Myeongdong, Jongno-gu, Sinchon, Hongdae, Itaewon). Additionally it is right next to a couple of convenience stores (three 7-11s), cafes, restaurants and a Lotte mart. The Yongsan station is a 15 min walk from the apartment where there is a huge mall with a large e-mart where you can get anything from groceries to luggage. The Yongsan station is also a KTX station.
There are air conditioning units in all 3 main rooms (3 bedrooms and living area). Our stay in Seoul was in October and the weather was cooling down, but we had a few warm days and the air conditioning made our stay very comfortable. This apartment would be ideal if you are traveling in summer. The unit has a nice cozy vibe and warmth to it.
Highly recommend this apartment.