We had a fantastic week long stay in Heike's apartment, which is better in real life than the pictures show! Modern, spacious, very comfortable and quiet.
The area around the apartment we thought was fantastic, many good quality food places and small boutique shops. Recommend the cafe just downstairs for breakfast. The area has a good vibe and is safe at night.
The U-Bahn is only a 5min walk which we used daily for getting around the city, tickets are easily purchased at the station (note they don't take VISA).
Heike was great and easy to contact when needed, she met us when we arrived from the airport and explained how everything in the apartment worked.
Thanks again Heike, we hope to return again some time soon!