We stayed for 3 nights in the apartment and enjoyed our stay a lot.
The apartment is very well located - the quarter itself is very nice and quiet, it is close to the centre (without being swamped with tourists) and close to the Donaukanal. We appreciated particularly the proximity to the Donaukanal - in the morning for jogging, during the day for a walk and in the evening for having a drink in one of the many nice bars and restaurants.
The communication with Ivan was very good. He was a wonderful host and very welcoming.
All in all a place to recommend for those that want to see not only the touristic facets of Vienna and want to feel welcome!