I stayed at Christian's place with my parents when they joined me in Vienna. We asked for early check-in and Christian said we would be able to drop our bags off at 1pm but not properly check in as the cleaner would still be there, which seemed reasonable. However, my parents arrived at the apartment early at 12 and Christian let them in, chatted with them until I arrived at 12.30, and the apartment was all ready for us even then. We really appreciated this. I was there on a work trip so he was even kind enough to provide us with a set of extra keys so I could come and go separately to my parents, which made our trip hassle-free. Christian lives in the same building which means he was always available and I would have felt comfortable asking for help any time. The apartment itself is beautiful, clean, definitely big enough for 3 and as a bonus has a bath. There are small homely touches like flowers and nice furniture. The location is great, with a supermarkets 2 mins walk away and lots of restaurants nearby. If I were to offer any criticism at all it would be that the walls were extremely thin between the two bedrooms (not great if your parents get up earlier than you and chat). We loved our stay and will definitely recommend it to friends.