This is a very large apartment, handily located close to the Belvedere and with easy access on foot or by tram or S-bahn to other parts of Vienna. The neighbourhood is quiet and safe, and there are restaurants and supermarkets close-by (but note that supermarkets are closed on Sundays in Vienna, so be prepared if you arrive on a Sunday, as we did).
We enjoyed great communication from our hosts, who very considerate and accommodating of our needs, and helped to make our stay in Vienna very enjoyable. I highly recommend this apartment.