This is a nice, quiet, modern loft in the Hackescher Markt area, a station which is very active with stores and eating options. The apt is a couple of blocks away from the activity so it is both tranquil and very well connected.
The only qualm I had about my stay was the communication with Marcus and his team. I asked a few days in advance about the facilities (if the washer/drier was working -- the washer was ok, but i couldn't get the drier function to heat); and then, a couple of days before, how was the check in supposed to take place. Never got an answer until after I got to Berlin Airport (so about an hour before check in), which made me somewhat anxious in the journey because I didn't know if I would be able to go online and check.
Fortunately, Berlin has good wifi in most public transport stations and airport, so in the end there was no problem.