Great apartment to experience Berlin, both for short-term and longer-term stays.
Location is perfect - very quiet street nested in a lively and historic area with plenty of restaurants and bars in all price ranges. Equally important are the transport links - direct train connection to airport and Berlin Central Train Station, as well as more local subway links.
The apartment itself is very comfortable - it's spacious, peaceful (sheltered from the already quiet access road) and nicely furnished. The brand-new kitchen was a particularly enjoyable to use. Neighbours were also welcoming without being intrusive in any way.