Just stayed 5 days in this apartment and we didn't want to leave. The first day we arrived by train from Rome and were worn out from travel, so Ingela took our bags until we could check in. She was extremely helpful any time we needed anything. There are a few pages of local information and house rules to read when you arrive, and if you have a flexible itinerary, take some of her itinerary suggestions. We discovered that fantastic bakeries are a short walk away. I recommend Der Mann der Verwohnt (I think it means the pampered man? I didn't ask), especially for breakfast. Stroeck is also great.
Also, Goldmarie is great for lunch (a little further away than The Pampered Man). I read mixed reviews but this was the best food I ate on our 3-week trip.
The area around the apartment is nice for an evening stroll and the subway will take you anywhere you need to go. Schonbrunn Palace is also within walking distance.
The first day we stayed in and watched a movie Ingela left in the apartment. There is a pile of brochures in different languages, books on the bookshelf, movies for a night in, and about every amenity you can think of. Every time I needed something, I would just look around and find it. Don't forget to sign the guestbook which is located in a drawer near the TV. I didn't find it myself until moments before we left.
Vienna was very kind to us, and this apartment was a big part of that. Thanks Ingela!