Unfortunately we haven't had the chance to stay at Aliz apartment, since our flight was canceled due to a strike with less than 24h advance on the apartment check-in. We've contacted Aliz as soon as possible, asking her the possibility of a full refund or a date change, knowing that we were aiming at an exception to the rule, due to the unpleasant situation. Sadly, Aliz has not made this exception, so we paid the apartment without using it :-(
Surely we'll visit Wien in the future, but we'll look for an apartment with higher flexibility on cancelation.