We didn't meet personaly the owner, she send us all of the instructions to enter to the apartment one day before our arrival. You'll find keys in a box next to each doors which is practical but very impersonal. We had a nice time in this apartment which is very close to supermarkets and public transports (around 30min by transport to go to the city center). A price's ticket is 2,40€ but we bought 48h time ticket for 14€ which is very pratical to reach several points of the city.
Enjoy Wien !