Location, location, location – Daniela's apartment is smack in the middle of Vienna's Innere Stadt, literally only a few minutes by foot away from the Hofburg, Staatsoper, and Stephansdom. All other sights and neighborhoods are easily accessible from here as well: Buy a weekly travel pass and simply hop on any metro or tramway to navigate the city if your feet should get tired.
Despite the central location, the apartment is very quiet, and we had a great night's sleep—until 7am, when the church bells started ringing. Also be aware that you're staying in a residential building and you may hear your neighbors talking over breakfast in the morning.
The kitchen is well equipped, and we had everything we needed. The Nespresso machine was a nice touch to get us going in the morning (there's a Nespresso shop around the corner to stock up on capsules). The minimalist bedroom offers a comfortable bed and plenty of storage. The equally minimalist living room sports a comfy couch and a flatscreen TV, but why would anybody want to watch television when you have such an amazing city at your doorstep? The apartment is on the 3rd floor (US: 4th floor), and there's a small elevator that helps hauling the luggage up and down.
Lastly, Daniela is a great communicator; her responses were quick and helpful. We were happy to have her as our host, even though we didn't meet her in person.