We were a longer term stay for 6 weeks.
This is great place to get a sense of what a local neighborhood feels like. The neighborhood still has some nice attractions, like the Plaza de Masadas, which is the spiritual heart of the area. There is also the nearby Rambla de l'Onze de Setembre where you can find lots of local shops, cafes, bio markets, churros, basically anything you need. It is also very close to the Metro Line 1, which takes you directly into the city center, or the L5 which can take you directly to La Sagrada Familia.
The house itself was more than enough space for us, and Arrate was gracious to permit us to bring our older dog with us. As others commented, the bathroom can be a little tight, but this is something we are used to in Holland, so it was something we adapted to without issue. The roof top terrace(s) were nice, and the larger one still got some sun in the afternoon for an hour, even in December.
Arrate lives nearby and we met her a few times to exchange info or ask questions. Everything was very easy to check in and check out.