Donya's flat is in the center, so you can reach a lot of beautiful places easily by foot. We wanted to see museums and a concert in Museumsquartier, and it is in the neighbourhood.
About the flat: it's real huge. You will have everything what you may need for a comfy short stay (or a long one, but we only spent a day in the city). We didn't meet Donya at all, so it felt like we have a flat in Vienna for one day. The environment is calm, no noises from the street is sneaking in. I recommend it.