I stayed at Friederikes place for about a month and the place was absolutely great. It's locatad a short walk (15-20 min) from the absolute city center, but quiet enough to provide a good night sleep. Place has two balconys and two bedrooms which is great if you have a friend visiting you.
Internet is fast and reliable (download) but upload speed might be a bit on the slow side if you have very demanding work. For 1 on 1 videocalls it worked perfect though.
Neighbours are best possible and I was never disturbed during office hours.
Friederike herself is a great host, who met me in person and provided some guidance of the close neighbourhood. Only thing I missed was a microwave oven for those short lunchbreaks when you neither have time to cook or wait for delivery service.
5 out of 5!