I had great experience staying at Boltzmann. This is my second time staying here. Room is spacious and this time they gave me one with a nice balcony facing the city. Bed is comfortable and the location is nearby to city, only couple of metro station. Room is clean as well. My only critics would be the breakfast, its too expensive for Euro 14 per pax compared to other hotel. Hotel staffs are very helpful especialie Natalie. Thank you Boltzmann.