All in all, our stay in Dortmund in this apartment was perfect. The apartment is fully furnished, from the TV in the living room to the suite of dishes and silverware in the kitchen. Whether you're staying for one night or a week and a half like us, you won't have to worry about towels or the toiletries in the bathroom, or anything related to the apartment. The landlords do a great job of maintaining and furnishing the apartment
Speaking of the landlords, Julia and Hauke are fantastic. They live on the second floor of the building, but did a great job giving us plenty of privacy and were very attentive to anything we needed. None of us speak German, but they speak English fluently.
Finally, this apartment is in a very choice location within Dortmund. Walking into the city is a fairly short 20-30 minute walk, but you can also take the nearby subway station which provides 10-15 minute access to the Hauptbanhof. There's a bakery and kiosk down the street for breakfast and late night beer/snacks, and further down the street is a Dursty beverage supplier and an Edeka supermarket. Outside of a pharmacy, everything is within a 5-10 minute walk.
All in all, whether you're a foreign tourist to Germany or a German looking for a nice place in Dortmund, this is the nicest place you can find.