Amazing apartment, at 3 minutes walk from Friedrichstrasse Station, exceptional location for visiting main Berlin attractions. First thing that surprised us was how HUGE is the apartment (we don't realized this in the pictures) : two bedrooms, a huge living room, a huge kitchen/dinning room with two sofas). We were a family of 4 adults but it was big even for us.
Contact with Elfie and Pablo, and her housekeeper Dagmar was perfect. Dagmar was waiting for us at 21.30 h, to show and explain us everything. We needed to contact her for a minor issue with the fridge, and she answered quickly, and told us how to solve the problem. For check-out, we simply left the keys inside the apartment.
Heating was super (and we really needed it!), beds were comfortable, wifi, appliances and washing machine worked perfectly, and the building is big but very quiet. It is two blocks from Friedrichstrasse (use the passage across the Hotel Eurostar) where you can find a Rewe supermarket, and places to eat and shops. The neighbourhood seemed secure, we went to see the new Year's fireworks, and returned walking at 1.30 a.m. without problem. We loved this apartment and we recommend it definitely!