I recently stayed at Hegergasse 17 at the Belvedere,it is a roomy clean apartment,with every amenity that is promised and more,the owner Christine was right there to meet me,when I came in late at night and was always ready to answer every question I had,the apartment apart from being very clean is very conveniently situated minutes from a pharmacy and several supermarkets,it is only a 5 min walk to the tram stop that takes you within 7/10 min right into Vienna city centre, I can recommend it to everyone.