I have stayed at Angelika's place for three weeks during my holiday trip to Berlin in January 2017. I unreservedly recommend Angelika as a host and her beautiful and very centrally located apartment.
The location is ideal: as i like to explore cities by foot it is a walking distance (google maps in a great help) to many local attractions. Kudam, the main shopping street, is just next door. On a sunny Saturday morning it is nice to walk to 17 Juni flee market and then have country style branch or dinner with a glass of wine in Cafe am See in Tier Garten, which is just across the road. Sybelstrasse itself is a quiet small street tucked behind Kudam but has lots to offer: there are grocery stores, bakeries, cafeteria and pubs. From Kudam one can easily get into any other part of Berlin as bus and underground connection is excellent.
The apartment is great: very clean, cosy and fully equipped. Angelika is a very hospitable and caring host: none of your requests or questions will be lost without her attention. I thoroughly enjoyed my visit to Berlin and being hosted in this apartment has made it only more enjoyable.