Key pick - up at a store nearby (approximately 2-3 min. Walking), exact instructions how to get the keys and how to drop them off! Throughout our stay we were in contact with the concierge of our reservation, got all the information we needed, fast replies!
For us the perfect location: about 5 minutes walk to the Metrostation, 1 min walk to the next supermarket, many bars/restaurants around. All in all a quiet neighborhood, we felt really safe walking around late at night.
Max. 15 minutes metro ride to most tourist attractions.
We walk a lot, so a few you can also reach by foot from the apartment, if you want to see more than just tourist spots.
Overall we enjoyed our stay!