Bert's apartment is the perfect compromise between finding a cheap accommodation and being centrally located. The apartment has a good transport connection with the rest of the city, while being located very close to Boxhagenerplatz and it's many bars/restaurants/cafes. The price per person was lower than the average for apartments of the same kind (don't think it could be possible to spend less for 4 people). The self check-in super easy.
Only the apartment is on the ground floor and the windows are shaded. It's the ideal location if you're looking for a place to mostly sleep, while visiting the city during the day.