Great experience. Natasha was very nice and flexible with out check in since we had super late flights getting in. The apartment is close to two metro stations (walking distance) and a cab from there will run you about 6 euro. Some cabs wont come directly to the door of the apartment as it's a pedestrian only zone apparently but walk 3 blocks and you see cabs lined up.
The apartment itself is very cute. Small but perfect for a couple or a small group of friends. It has stairs and no elevator/lift so pack light. Overall super great experience.