The overall experience was very nice. The apartment is very well placed, within a quiet neighborhood, close (5-10 min) walk to all major transportation points. Also, one major advantage is the position near the Schönbrunn Palace as this is one of the main attractions of the city and u need at least one day if not more to enjoy what it has to offer.
As for the guest, Daniel had offered quite a bit of information covering most of our questions and the check in/out process was probably one of the smoothest we had.