I really liked this hotel ! I was staying in this hotel for 4 nights with my two 7 and 9 year old sons and was impressed about the size of the room, it was enormous. However be aware of course that not all rooms are the same, as the hotel used to be an old apartment building. Very cozy and with a nice charming antique feeling. Staff was helpful, providing maps, directions, information, etc. Breakfast was ok, nothing spectacular (different cereal, eggs, bacon, different bread, fruits, etc.) ... the usual, but for the price it was very good. Wi-Fi was very good, I managed to use Skype through it with no hassles. The location is very good, probably about 20min with the underground/U-Bahn to Alexander Platz with only one changeover.
If I had to complain about something, it would be they forgot to fill the mini bar with beer twice :) which after walking with 2 children for 6 hours at 37C (not kidding), I was dreaming with that beer upon arriving to the room. I would definitely recommend this hotel !!