We recently stayed in Tobias' apartment in Berlin. From the moment we walked in, we were impressed--spacious and stylish and clean. We absolutely LOVED the apartment. There are (3) bedrooms, one even has a balcony that overlooks the street below, which is a plus. The WiFi was fast and we had no issue, which was great.
Also, it is about a 1/2 block away from the UBahn station, which is super convenient. There are also small convenient stores in walking distance as well as restaurants. I can't recommend this apartment enough. Tobias' communication was good and the check in process was easy. We were met at the apartment upon arrival, and (3) sets of keys were provided for me and my (2) travel mates.
The only downside--which for us was NOT a problem, is that you must be able to climb three flights of stairs. We found in visiting Berlin in general that most places (especially if they are older buildings) require you to use stairs and don't have elevators available.
The apartment has a washer and dryer (the dryer extremely rare to find!) and the kitchen had all of things one needed such as pans, glasses, silverware, plates, etc. The pantry also had coffee filters, salt, pepper, etc, which was again very convenient.
If I visit Berlin again, I wouldn't hesitate to stay at Tobias' apartment.