I want to preface and say that I have never written an Airbnb review in the past, but unfortunately this was one of the worst experiences I've ever encountered.
First, the communication with the host was disappointing. We arrived in Vienna without check-in information and were forced to contact customer support to get in touch with the host. Upon arriving in the flat, the room and towels reeked of cigarette smoke. The towel also had stubs of hair that must have been from the previous guest. On the day of our check-out, again, the host provided no instructions on where to leave the key, etc. As we had an early train to catch, we had no choice but to improvise last minute - this could have easily been resolved if the host was more responsible the day before.
Overall, our stay was an extremely stressful experience and was not worth the value for such cleanliness.