I would highly recommend this apartment for anyone wishing to visit Vienna. I went with 4 friends for 3 nights and it was great. The location couldn't have been better as everything was in easy reach. A 10 minute walk gets you into the lively part of the city, there is an Aldi 2 minutes away for when you need supplies and the nearest metro station is 5 mins away (there is also another metro station 10 mins away which can take you to Wien Hauptbahnhof train station in 7 mins without needing to change).
Thomas, who was the person I communicated with before arrival and who let us into the apartment, was super friendly and gave us some great tips for where to go.
We all had a great time in Vienna and this apartment was great. You won't be disappointed.