We highly recommend this small apartment which was clean, well equipped and remarkably quiet for such a central location. Christina's representative Manuel was very helpful and the printed tips in the apartment were spot on. We especially enjoyed our meal at Gasthaus Woracziczky but be aware that, like many small restaurants in Austria, they do not accept credit cards.
Only thing to be aware of is that this apartment would not be suitable if you have mobility problems. It is on the second floor of old Viennese building without a lift so there are a lot of stairs to climb!