The flat is located close to Sagrada Familia near public transportation, on the ground floor towards the back of the building. There was a lot of construction outside that we were first nervous about, but thankfully being in the back we didn't hear it.
The flat left a little to be desired - there is little to no natural light so it felt like a cave. Basic essentials were missing - hand soap and body soap. The bathroom and kitchen weren't totally clean, and there were flies in the kitchen.
Esther's communication, however, was great - she was responsive within 5 minutes to my questions about check in. Also, the flat can fit four - five people as it has four beds: a loft, master bedroom, and bunk bed with two beds. I did find it strange that the bunk bed room's beds did not have sheets and mattresses looked a bit dirty.
I'm not sure if I would recommend Esther's flat - maybe for a group who is merely looking for a place to sleep.