The apartment is amazing -- on a mostly quiet street, yet walkable to all of Old Vienna. Apartment was clean and well appointed, beds very comfortable with lovely linens and good pillows. Friday and Saturday nights there is a bar nearby and you could feel the bass beat of the music (it is open until 4 am) but it didn't bother us. Lots of space to hang out. Only issues for us were the poor quality towels (felt like rough sandpaper) and the lack of lighting in the living room at night -- only some recessed lights in the bookcase and one lamp. Could also use some more counter stools (there is only one).
Would definitely stay here again, might bring my own towels!