I traveled with my girlfriend and we chose this guesthouse because of the price. The building is pretty old and the rooms are very simple. But what really made our stay was the host, Mr. Kim. Very, very kind and attentive man. He gave us maps and taught us all the perks about moving from the guesthouse to the main places in Busan (the guesthouse is pretty far from downtown, btw). One night he invited us and other guests to go to some sort of mountain sightseeing spot, where you can see entire Busan. He would take everyone in his car. My girlfriend was not feeling well so we didn't go. But before he left with the other guests he drove me to a pharmacy to buy some medicines for my girlfriend. He also speaks the minimum english to supply all the guests needs ^^
And just a tip: if you're going by train, book your tickets to Gupo Station (구포역) instead of Busan Stantion (부산역). Busan Stn is very far away while Gupo is so close to the guesthouse. And all the trains stop at Gupo when arriving or leaving Busan anyway...
If you just want a fine place to sleep, I highly recommend this guesthouse. We would surely stay there again.
Last notice: the guesthouse does not have it's name written in english at the entrance of the building... So if you cannot read korean, look for "You r my sunshine". It is what is written besides 유선 게스트하우스 (Yusun guesthouse in korean)