We vistied Vienna for 4 days and had a really nice stay at the apartment "Karlsplatz". The apartment was nice, clean and comfortable and it comes with everything we needed. We also loved the fact that a Nespresso coffee maker was included ;-)
It's only about half a minute away form the underground station. But it's quite central so we made most of our tours by feet.
Communication with Melanie was perfect and she helped us out with some advise about tickets, places to visit and where we would find a nice place to eat.
We definitely recommend this to everyone!