Ms. Han's apartment is in a nice and quiet neighborhood , and major street "Valencia". It's literally less than 10 minutes from the Barcelona Sans Station. For those who have a heavy backpack or lots of luggage or need to catch an early train, it'd be a perfect choice. Also, it's within 10 minutes walking to the famous royal palace/plaza Espanya (the music fountain), where the Olympic mountain is just behind. There're two metro station with a radius of 300m. Location-wise, you can easily get around by public transportation. To me, who loves walking, it's also not bad! I went to see how gaudi's walk (include park guell) by foot and it's awesome. I feel walking is the best way to explore Barcelona. (Walking back late is safe too.)
The room with the single bed is quite tiny but it's very clean and comfortable. If you're gonna stay outside for at least 10 hours, and only use the room to get rest, it'll be cool.
Ms. Han and her husband prepared breakfast for me everyday and they really made me feel like home. I can't thank them enough for the great accommodation in Barcelona.