I would definitely go back again. The location was very convenient - on the same line as St Stephan's and St. Charles' stops. We had our excellent morning coffee at the Tchibo across the street, and there is a Billa supermarket if one wants to make use of the well-equipped kitchen (includes microwave and toaster, and wine glasses!), which we did. They even supply slippers, like many of the Asian hotels do. And there is daily cleaning, unlike many of the hotels where the rooms are cleaned once every three days, or upon request. Whoever did the cleaning did a really thorough job.
For people arriving before the official check-in time and wanting to store their luggage, there is a lack of clarity around how to access the luggage storage room and the apparently limited amount of secure space. I found the luggage room unlocked with six lockers, all locked. So there was no way for anyone to use the lockers or otherwise safely store their luggage, unless a person physically came out to allow guests to put in their luggage and then lock the room afterwards. Another guest arriving at the same time as we did called the staff about storing their luggage but they didn't receive a satisfactory response and decided to come back at check in time.