Fabulous location in the historical Innere Stadt! Many wonderful restaurants and cafes within walking distance, in addition to be very close to important sites (the Hofburg, museums, Spanish Riding School, Kohlmarkt, Graben, Holocaust Memorial, Stephansdom, Rathauspark etc).
This is a super place to stay if you're going to be out and about a lot. During the week, you share the apartment with the office that is in the living area (the person I met was very nice). The full kitchen is also great; pots, pans, plates, utensils, but no salt/pepper/spices, so you might want to bring some from wherever you're getting your food if you plant to use the kitchen.
I gave four stars because it doesn't have really have a comfortable place to relax/hang out, in contrast to a lot of places I've stayed that have living areas like that, in addition to offering breakfast/snacks/etc.
This is a great place to have as home base if you're going to be doing a lot of sight-seeing.
Communication was prompt and friendly - an overall very nice experience.