The apartment and the communication beforehand was fine. The location of the apartment is great. If it would have been only for that I would have given 4 stars.
Unfortunately after the stay and after everything was already paid, I was asked to pay additional 100€. The problem was that there are two beds and the first bed (convertible couch) used, is very uncomfortable therefore the more comfortable bed was further used. (Only one person was staying at the airbnb)
The argument why 100€ were demanded was that there was another person sleeping in the airbnb. That was just not the case and even after clarification, the demand was still not drawn back. So because two bed sheets were used instead of one I was asked to pay 100€ more. That seems very unreasonable and therefore was very annoying!
I think if one knows this beforehand one can work around that issue. I then recommend sleeping in the small bed from the start of your stay. The convertible couch whatsoever is not recommended. This only works if you are traveling on your own.