The hosts were nice and kind and provided a lot of great tips about Prague which was incredibly nice.
The apartment, on the other hand, was not so great. When we first arrived, there was a subtle smell of mold which I did ignore at first, but my girlfriend said it was quite powerful. Also, the apartment was incredibly cold. When we increased the heating and stayed the night, the smell became more and more noticeable due to an increase of humidity in the apartment. My girlfriend started coughing and I also started feeling a bit out of air.
We requested the second day to be given an alternative to stay and we got one. Unfortunately, the new apartment was in a worse state than the first one. In terms of furniture, space and overall comfort. No mold though which was a relief. But still, we felt that it is not okay because the second apartment photos were looking waaaay better than the reality.
In the end, we contacted airbnb support and they gave us a wonderful acommodation which we are very happy about.
I do not think these are bad hosts at all! They were very nice and welcoming. Problem might be the internal communication and the investments in the apartments.