The booking went very smoothly. The location is not very central to Berlin, but the Underground and buss lines are walking distance. I didn't mind that at all as you always need public transport in big cities.
The apartment is clean, well equipped, bathroom is very nice, kitchen roomy with lots of equipment, including a good coffee machine, dishwasher,....
Apartment is very light and has a lovely terrace for enjoying coffee.
WiFi works well.
The only minus was the fact that the apartment is supposed to be non-smoking but I could smell the smoke slightly. - it is creeping in if the apartment is close for e.g. whole day. But you can always open windows...and it goes away.
All in all, I had a wonderful stay and I would recommend the apartment!