We stayed for 3 nights in Helena's studio and we really enjoyed it a lot. It doesn't look exactly like in the pictures (furniture was moved to other position and some new furniture has been added) but the truth is: the apartment is much better than the pictures show!!
We actually met only Helena's husband, who is very friendly and gave us lot of useful tips and advice about the city.
The only little shadow that was cast: the water pressure in the shower was sometimes very low. Helena said that everything was newly installed, and that is true; but I guess with old houses and the bathroom being the top most room of the house, so one has to accept this.
Nonetheless: We highly recommend Helena's, the stay is worth every cent you spend! This was the best Airbnb experience we had so far.