We had a great stay in Nina's apartment!
The apartment itself is nice and clean, and has everything you need. The connected lock is really handy if you're a family/group and want to be able to come home at different times.
We did not spend a lot of time in the apartment's neighborhood itself, but it's right next to the Sagrada familia for those interested :)
Communication with Nina was easy and fast, even though we did not meet.
Would definitely recommend for anyone who would like to stay in Barcelona for a reasonable price, but with all the comfort you can find in higher priced apartments.
Thanks Nina!