We really enjoyed our stay - apartment was clean and located in a really nice quiet neighbourhood with cafes and restaurants at your doorstep. Only a 10 minute walk to Stephenplatz.
However be aware as there is no 2nd bedroom as advertised (Apartment is listed as having 2 bedrooms) - it is in fact the lounge room with pull out couches. Curtains didn't block out light and some were missing, so sunlight shone through from early on in the morning and street lights of a night time. Lots of evening noise from cafe below and also noise from tram which runs right around the apartment late into the night. If you can look past these few issues, it's a lovely place to stay.