Great apartment - anything a couple needs for a stay in Berlin and more.
Nicely located in Kreuzberg, close to U-bahn station (from which you can easily ride to most parts of the city).
Access is a bit challenging - 4 very steep floors with no elevator (pay attention if you have heavy luggage). Also, only one set of keys, so if you split from your travel partner - one needs to come down and back up in order to open the main door for the other.
Other than that - great place - clean, beautifully designed and very quiet. Recommended!