Overall a good stay, and matches the listing :)

Pros:
- Very very very comfortable bed!
- Really close to center, easy access to tube
- Clean, warm and feels secure
- No sound from the street at all, well insulated
- Nice & modern & very clean
- Fast internet
- Katarina had printed loads of tourist info for us and spent a long time telling us all the great things to do in Vienna :)
- Very competitive price
- Let us leave bags until the late afternoon

Cons:
- There was a fairly strong damp smell, flat doesn't have great ventilation. A mixture of no bathroom fan & lots of wet heavy laundry being left to dry in the kitchen (not by us) meant the air was humid.
- The main station nearby (Praterstern) didn't feel very safe at night, especially with a lady: groups of youths/homeless/beggars lurking and quite dark. Recommend using Nestroyplatz U-Bahn not Praterstern. It is not the best neighborhood but is perfectly nice/busy during the day.
- We had given our landing time and asked how long it would take to transfer, and given our arrival time based on that. We arrived 30 mins after our stated arrival time (3pm) due to the train taking longer than expected. We were asked to leave an extra 10Euros to cover this 'late fee'. The house rules had said it is 10 Euros per hour late - however we felt that since the time was only 30 mins and we had been guided by the host, this was a little bit of a surprise.