A great place to stay in Vienna. A few minute's walk away from a major train/metro station with plenty of stores and restaurants in the area. Check-in and check-out was simple and hassle-free. Host was kind enough to allow us to keep luggage until the early afternoon; also provided quick replies to any questions. Apartment itself is very upscale and modern. Very good value if you're travelling in a group of 3-4.
Of note, in early summer of 2019, the elevator in the building was not functional. If your party may have issues with using stairs for a few floors, make sure to check with the host on the status of the elevator. It was no problem for my group.
Highly recommended based on our experience.