I stayed in this guesthouse for three night, in a mixed dormitory with 10 beds. The room itself was quite big, and I appreciated the fact that even if it was full it was silent, during the night I could sleep.
This hostel is located in a very good position, only 2 minutes from the metro station, so it's very easy to visit the city from there; you can also have a walk and reach the center of Gangnam-gu area in less than 30 minutes.
There's also a common room with a kitchen, I never used it but it looked functional if you want to cook your own meal inside.
Actually the only problem that I noticed was about the reception: they are not 24h open, but only from 9 am to 11 pm. In addiction they are not there in the morning from 11 to I don't remember what time because they are cleaning, then they make a lunch break so they are absent for another hour and in the end they have another break for dinner, so from 6.30 pm to 7.30 nobody's there.
When I arrived it was around 7 pm and I didn't know about this dinner break, it's not mentioned anywhere on their website or social media, so I had to wait for while to check-in.
Anyway this is a good compromise if you don't want to spend lot of money in accommodation and you want to be very close to public transports.