We were a family of four and stayed at Birgit's apartment for five nights. Its in a quite street, but very convenient to get to the center. The tram is literally just outside the apartment and we have all loved to use the tram.
The place is super clean and comfortable. Though you have to be very quick with the showers as the hot water doesn't last very long.
Birgit has been very responsive and friendly.
Overall, we loved staying there and would recommend it or stay again.