The appartment was very nice and our stay there (4 people and 3 nights) was relativly fine. The flat is located on a ground floor near a very busy streed during weekdays since it is an industrial area so it was very noisy. It does have double glazed windows so if we closed them the noise was gone but it was a bit too hot then.
The appartment is close to the subway staiton, although it is not close to the city center with the nice Berlin transport system you can get everywhere within 30 min or so.