Gitta and Niels' apartment is well-located, it is easy to walk to the "touristic" city center (15-20 minutes) and to the main museums. Metro station is 5-10 minutes walking distance (metro takes you directly to the airport, around 15 minutes). In the neighborhood there is all you need, bakery, supermarket, pharmacy, cafes and restaurants.
The neighborhood is nice and quiet. The apartment is not directly on the street so you hear absolutely no noise from the street ; anyway the street is not a busy one so it's very calm.
The apartment is really tastefully decorated (actually nicer than the photos show it) and practical. It was perfectly clean and the bed was made as we arrived. Gitta's friend gave us the keys as we arrived and when we left, all we had to do was leave them in the apartment, so it was really easy.
The only disadvantage was that some of the neighbors were noisy and we could hear them 2 or 3 times in the week playing music...
But otherwise we had a really nice stay at Gitta and Niels' beautiful apartment.