It was great living in Daniela's flat. My girlfriend and I were there for 3 months and haven't had any problems with the flat, functionality of any appliances, nor heard from the neighbours. Daniela and Philippe were always reachable.
The flat is newly renovated, so most of the furniture is new and modern, with a vintage touch. Only slight difficulty was that it took a while until the dishwasher was fixed (but it was Christmas time, so it was understandable).
Everything fits perfectly for two, but there's still enough room for inviting friends, especially in the bright and spacious living room. Neighbourhood is quiet and seemed very safe. All public transportation is nearby, just 5 min walk to different tram lines, train station that connects to the airport and numerous bike-sharing and car-sharing options. Also, numerous groceries shopping options are at hand. The city center is about 20 minutes walking distance (or less with public transport). They way to the city center is also very nice.
Really felt like home for a while! If we come back to Vienna, we will definitely consider staying there again!