This is a really fantastic apartment, and I couldn't be happier with the location we chose for our first trip to Vienna. It is not a stretch to say it is around the corner from the Hofburg (the historic winter palace of the Habsburg emperors).
(You literally walk two blocks, turn right, and there it is down the street, in full view. How cool is that!)
Beyond that, the apartment is a couple short blocks away from multiple public transportation stops - so you can get to anywhere else you'd like to go pretty quickly.
As far as the apartment itself, it is spacious, works well as a two-bedroom, and included all amenities we hoped for. You can close the door to both bedrooms, which are separated by the kitchen and common areas. As such, we had no need to worry about disturbing our friends in the other bedroom on the way to the bathrooms (separate toilet room and bath/shower).