First of all the apartment was exactly as it appeared in pictures.... Gorgeous. It was beautifully furnished, stocked with anything we might have needed and very comfortable. The location was fantastic. We could walk everywhere in 15 minutes and when we needed to get to Duomo the morning we were leaving before heading to our train, it was 7 minutes away. Our host was responsive and kind and his colleague Nico took fantastic care of us the whole time--- spending 30 minutes showing us great restaurants and bars in the area.
The only problem we had was that the water boiler wasn't working so there was no hot water during our stay (we were there during a holiday and weekend so no technician could come in). However Luca and Nico were very very responsive and tried their best -- Nico even came to the apartment twice to try to fix it himself. At the end of our stay Luca gave us a partial refund without us having to ask.
It was a great experience. My friend is going to be staying in the same apartment for her mother/daughter trip in September and I would recommend it to anyone else as well.