We loved our stay in this beautiful modern apartment, and joked many times that we were moving in! Check-in with Ilona's helper Shari was breezy, and he was quick to respond with help when we had questions about the fireplace. The outdoor spaces were absolutely lovely, and the sun room (winter garden?) was an awesome bonus.
The apartment seemed to be on the outskirts of central Vienna, in a calmer, more residential area, which was great for getting sleep and enjoying local restaurants. It isn't near many tourist sites, though, so it wasn't an easy trip back mid-day. I wish we'd had more time in Vienna, partly so we could have spent more in the apartment!