Ideal location right next to the main train station and public transport. The apartment was clean and very convenient. Katharina and peter provided tea and coffee, which was great to bridge the time till breakfast at museumsquartier or palmenhaus.
Peter offered to lend us a month-ticket for public transport, which was a bit cheaper than a 3-days-ticket. On our last day in vienna he even came to the train station so we could use the ticket until we got on train in the evening, which was very lovely!
I highly recommend this apartment.