This is a great place to stay when you're a few days in Berlin. It's walking distance from two U-bahn stations in a quiet neighborhood just off bustling Potsdamer Straße. Plenty of food and bars in walking distance but none of the noise that often comes with staying in the vicinity of it.
The apartment is very spacious with a very high level of finishing. Bed is comfortable and the shower is powerful and easy to get to the right temperature. The kitchen is simple but you can prepare breakfast and evening meals there, no issues. The TV/media setup could do with an instruction or simple manual because it's quite sophisticated. And during my stay, the wifi didn't reach the kitchen and living room area but worked just fine in the bedroom/office area. That should be an easy fix for the friendly and communicative owner!
I will certainly come back when visiting Berlin again!