I would recommend this apartment. The location is fantastic and near the city center. The place is sized and decorated perfectly for a couple or individual who are visiting Vienna for a few days to a week. The hosts, Eva and Michael, are very nice and respond quickly. We were able to store luggage after check out before we left for our flight -- which was very appreciated.
They also have a mobile hotspot you can carry around the city. Great for people who are traveling but need to stay connected to work / home.