I highly recommend Evelina's place. It is located in a great spot very near to Belvedere Palace, and a short walk to a number of public transport options. We even walked into the main centre of Vienna which was only a 20 minute walk so easy to do. The apartment was very secure and well appointed with comfortable furnishings and a comfortable bed. I especially enjoyed the little balcony which allowed me to sit outside with my morning cup of tea. :)