Diana's and Robert's place was fantastic. Located conveniently close to a U Bahn station and in a safe and quiet neighborhood this place was a great place to stay in for our first visit to Vienna. The appartment had everything you require and a lot of useful books and guides available. Although we never met the hosts the whole process was fantastic, the flexibility to check in and out at your own convenience and swift communication with the hosts. Highly recommend this place and a nice few places locally for food and drinks.