Stayed in a comfort room and I have to say the following:
Room is not 4-star by any means, more like a 2-star/
Old carpets, noisy heating system, outdated bathroom similar to a 2-star hotel for quality, no bidet as shown in the hotel pics. No fridge.
Advertised on Expedia as having a pool, no pool of course.
SPA area is outdated with lukewarm jacuzzi water,
The hotel bar was closed, for months if not mistaken.
Read some other reviews with similar comments and replies from the hotel were basically nonsense for a 4-star.
To summarize, the hotel is nice overall, breakfast is very well made. Room quality is far away from a 4 star hotel like a 2 star one, old outdated just ugly overall and they should not advertise the hotel as a 4 star at all.
Staff, asked what are the parking rules in Vienna and got 2 different answers, shall I say more?