This is truly one of the best Airbnb listings that we have tried and we will be happy to come back.
1) The location is great -- it just a couple of blocks away from Karlskirche, so it is easy to get there from the airport either by CAT and then metro or taxi (it took us 18 minutes to get to the airport on our way back to the airport. The apartment is very close to the city centre, so you can walk anywhere from there (or take a scooter). There are also several very good restaurants just a short walk from the apartment (e.g. Le’s or Meissl und Schadn) and a grocery store is on the other side of the street. You can also walk about 10 mins or so to Naschmarkt and get fresh produce / a selection of delicious cheeses.
2) Once you go through the front door you find yourself in a beautiful and quiet inner yard, with a lot of vegetation all around, which makes you completely forget that you are in the city centre. The place itself is very clean and comfortable and has all sorts of amenities you may need for a short or a long stay. Unlike many Airbnb listings in Vienna, there is a full-sized table in the kitchen/living room which is very comfortable to work at (mb, while sipping on a glass of an Austrian Riesling), which we certainly appreciated.
Overall, this is a perfect place for exploring Wien, and Peter is a kind and excellent host.