A friend and I stayed for nearly a week with Monika and it was a lovely experience. The flat is a bit north of the city center but we found this to actually be an asset. It meant that it was quieter in the area and a much less touristy. Great restaurants right around the corner and right across the street from a 24hr grocery store. We mostly walked into the center (20-60min) or took the metro (15min walk) but there is also a bus right across the street.
Monika's place was very clean and comfortable. She was helpful for finding restaurants and taking public transportation. Also an very interesting and kind person to speak with. Would stay again.