Maddalena'a flat is a wonderful place to stay for your next trip to Berlin.
Pros:
Location, location, location! The flat is central to everything and there are 2 subway access points 5 and 15 minutes away. All the popular tourist attractions in Berlin are within 15-30 minutes when walking/using public transportation.
There are multiple wonderful cafes, coffee shops, and restaurants on the same block as the apartment (food, beer, gelato, etc.). There are also 2 small food markets and a laundromat where travelers can get their clothes cleaned and/or just pressed.
The flat is very clean and modern with a nice balcony and views from numerous large windows on almost all sides.
Cons:
No air conditioning or fans make the high temperatures in summertime fairly uncomfortable for people who are unaccustomed to living without AC, but this seems to be the norm in Germany (no AC or fans). The flat would be wonderful during all other times/seasons of the year.
Bars/cafes just below the flat are convenient when you want coffee/food/drinks, but stay open late til ~ midnight, which can be noisy when you're trying to sleep and the street traffic is pretty loud as well. The windows offer good sound-proofing when they are closed, we just had them open most of the evening because it was hot when we stayed there in late August.