Stayed over a weekend. Hotel staff were great and very helpful. Massive fish tank is a great feature of the hotel. Highly recommend getting a room that faces the tank.
Didn't think 25 euros was an acceptable charge for breakfast. Nice cafés and bakeries next door which are much cheaper that the breakfast rate
The hotel overlooks a quiet small park square and is next to the main shopping street in Berlin through which all the hop on hop off buses stop. Underground close by. Hotel excellent with very friendly staff.