Everything was very easy and seamless. The place was huge, plenty of room for a big family. Be sure to note that it is 10 euro per person for linens and towels. Also, for visitors that need good internet, the internet only worked well when you were close to the front entrance door. Otherwise it went out when you went to either of the bedrooms and sometimes the kitchen too. I'm guessing it's shared from across the hall which is why the signal is weak in most of the apartment.
Anna was very accommodating, providing us a fan since Berlin was going through somewhat of a heatwave while we were there.
The washer worked great and the place was clean and location was excellent. I would definitely recommend.