This is a great place to stay at if you have a group of 4-5 people - the fact that it has 2 bathrooms comes in handy in the morning and before bed. The flat is clean and cosy, and there are these little things (like the window on the inside facing room, the building atrium, and the fact that it is totally not on the 2nd floor, in spite of what the elevator will tell you), that add a bit of character.
There is a living room, with sofa and a big round table, that i didn't see in the pictures - but that was where we all gathered at the end of the day.
The location was good, a bit surprisingly so - the neighbourhood feels more casual, homely (it's quiet at night), but still has good restaurants, Sant Pau, great views from the Batteries within walking distance. Sagrada Familia is actually close, but the rest of the touristy places aren't. But you'd probably use the metro or buses daily anyway.
Overall, it was a lovely time in Barcelona, and the apartment was a part it.