Laszlo's flat is a very good choice in Vienna. It is very conveniently located, close to most attractions, with a direct airport connection and even within walking distance from places like Schonbrunn or Westbahnhof.
My 5-and-a-half-year-old son and I felt very well there and had everything we needed: a clean and well-equipped space, a comfortable bed, a market and some supermarkets nearby, a quiet street.
Laszlo was very nice and patient, although we arrived later that we had expected and he provided all necessary information. He offered to help further, but we don't need anything. The self-checkout was very convenient, as we could free up the space when we were ready.
Overall, it was very good value for money.