First of all the host was very accommodating with a last minute change due to flight cancellation, which was the most important part of the trip.
I stayed for 3 nights, the apartment was small but with several amenities. For one person it was great. Clean and quiet and next to a train station. Transportation in Vienna is easy so I had no difficulties moving around the city. The building was old but the apartment is renovated, keep in mind there is no elevator. Would easily recommend for one person and anyone not planning on staying inside most of the time.