I've stayed in the hotel for 5 nights at Christmas time.
Very helpful polite and ready to assist staff. I had no trouble communicating in English. The location is excellent. The hotel has an underground station entrance literally next door. St. Stephan's Cathedral is within 15 minutes walk. The room was clean and tidy. The breakfast had excellent variety, something for every taste.
The room had no outside view. The window had frosted glass, when I opened it, there was an ugly brick wall of the neighboring building and a small inner yard. Not a big issue for me as I was returning to the hotel mostly to sleep and rest.
Breakfast section can get very crowded. I had breakfast half an hour before they were stopping to serve it, and most tables were still occupied. I guess it's worse at peak hours, so take that into consideration.
Overall - a very nice hotel, great location and friendly staff. I'd stay there again.