Loved the location, with very easy access to all that you need within the Ringstrasse but separated from the hyper-busy area by the Danube canal in a place with more of a neighborhood feel.
The apartment itself was nice, and the price is good, although know (as stated in the listing) that there's no kitchen or laundry use. But Vienna has a lot of good food and the apartment is literally next to a grocery store.
Four stars instead of five because on the penultimate day of my stay the building's water was turned off temporarily, unbeknownst to me, so I had to walk over five minutes to use a nearby public toilet (luckily it was free). Obviously Jack had no say in the matter, but I was not informed beforehand unfortunately, so I wish that was communicated in advance so I could plan in case of potential emergencies. I suspect Jack was also unaware of the shut off, but as a host it is a responsibility to ensure knowledge of such events. Other than that, though, Jack was a very pleasant host, though I only met him on the last day right as I was leaving. I had a wonderful time in Vienna, and would recommend this place!