Outstanding place. Camfortable and good equipped and clean appartment. Very close to the city center, metro and train stations but very quiet the same time. Interspar just at the front of the building.
I would only advise the host to leave some essentials such as salt, pepper, coffee, paper towel, which may be needed for the very first time guests need after a long and tiring journey to the apartment.
Also, probably to revise pillows that are not so comfortable.
Anyway , I would definitely choose this apartment for my next trip to Vienna.