The hotel was better than expected for the average rate I found in the site.
The neighborhood is good, silent, and the place is not very distant from the city center (15min in S lines). There are supermarkets and restaurants with reasonable prices.
I stayed in a single room, but with a large desk and reasonable space for the luggage. The maintainance of the room and of the bathroom seems good. It also has a kettle and tea bags (which were not in the description of the room).
The breakfast was also very good, with a variety of cold and hot options.
There was also a fan in the room, which was essential for a hot summer day.
If I go to Frankfurt again, this hotel will certainly be one of my first options.