Kurt was an excellent host!
Communication was clear and easy. Check-in was smooth and flexible. The apartment itself is spacious and accommodating.
The neighbourhood is absolutely brilliant, it's very close to a metro station (60 seconds of walking), quiet, brimming with restaurants, cafes, shops, a supermarket and so on. It was very central, but outside the busy touristy city center. The metro station is on the central line, and getting in and out of the city center is a matter of minutes. You get the quieter serene parts of Barcelona, with easy access to the bustling nightlife. It's also very family friendly. One place you cannot miss, is La Besnéta, a superb vegan bakery just minutes from the apartment.
Guille greeted us and let us into the apartment. He was very friendly and helpful, telling us some of the history of the city and gave us recommendations for our visit.
The apartment was fairly clean, however I did notice some dust in the closets. It was certainly plenty clean enough, but perhaps an area of possible improvement :)
One thing to be mindful of is that the apartment isn't very soundproof. You can easily hear people talking in the courtyard, running up and down the stairs, etc. The neighbourhood is very quiet however, and we had no problems with noise during our stay. It might be prudent to bring some foam earplugs though, if you are very sensitive to noise.
All in all, we were extremely pleased with our stay, and can heartily recommend Kurt's apartment for friends, couples or for a family.