It has been a pleasure to stay in this apartment! And a very nice bed I must say, we've slept very well. We could use two of the bikes daily and within 5 min you are at Warschauer Strasse, the centre of the east of Berlin. Carmen is very friendly and you can always ask her if you need to ask anything.
The only tip I have is to make sure the fridge workes well because it was so cold it was like a freezer. For storing drinks it was fine but food we couldn't store because of the cold temperature.