The apartment is in a great, very central location, easily within walking distance of all the main sights. Yes, it is up quite a few stairs but that's a known "feature" of the apartment.
Inside, the apartment was pretty much as described. It is fairly basic but is clean and in a good condition so was fine for us as we were only there to sleep. I think the only comment we had was the lack of storage space (drawers, wardrobes) for clothes. Not a major issue but did mean we lived out of our suitcase during the stay.
One thing did go wrong: the air conditioning unit was broken which meant the evenings were very uncomfortable during our stay. Hopefully Enrico fixes this for future guests.