I think my rating would be much higher if I had known some things about the apartment before I booked, so I am deciding to give a lower rating to balance out the 5-star average.
The main issues were that the Wi-Fi signal is very weak. Even with newly purchased devices, some could not connect to the internet downstairs and would often lose signal in the loft bedroom, where the signal is strongest. If a Wi-Fi booster were installed, that would improve things greatly.
Some other minor annoyances were that it's a first floor apartment, so you can hear a lot of noises from people coming in and out of the complex, and the streetcar or train nearby often rumbles and shakes the apartment. You could also occasionally hear footsteps from people upstairs.
The hot water also does not last very long.
This would easily have been a 4- or 5-star stay if not for the Internet issues. Enrico was very responsive to messages, and check-in and check-out was fairly smooth.