Communication with Flo and Nicolas was friendly with quick responses.
The apartment itself was exactly as pictured, clean and very comfortable.
The location was also great, plenty of good restaurants, cafes and cool shops within walking distance, 5-10 mins form the nearest underground station and with a bus stop outside the door, the tourist centre is also walkable in 20 minutes.
I recommend Nicolas and Flo's apartment highly, it's perfect for a visit to Vienna.