Dan's place was very clean. Great directions to check-in were provided by Dan and he is always responsive to messages. Most of all, the stay is in the actual heart of Vienna (not an exaggeration). Walk out of the apartment and it is a 2-minute walk to the busiest downtown street. My advice? Learn to use the underground (subway/metro), it is very cheap and can take you to amazing sites around the city.
Vienna is special.