I had a great experience at Joerg's place during my (3 months) stay in Barcelona.
The apartment is greatly positioned, very close to the main transport links, like Universitat 5 min. and Catalunya 7 min. walking distance, and also many bus stops even closer.
The flat is located in Raval neighborhood, in a quiet busy pedestrian street, my flatmates and I have always felt safe and comfortable in hanging out in the surrounding area.
The check in went smoothly. When we have had some small problems in the apartment Joerg was always very responsive and ready to solve any kind of thing (without charging us extra money). All the roommates are mostly Erasmus people so is very easy to communicate with and make new friends.
Everything was nice and clean. Good value!