Our first impression, we were a little unsure of the location because there was a market going on when we first got there and tons of people in the square with some faces that didn't look the friendliest. We left to venture around the area and see what was around and came back and felt a little more comfortable after the market workers had left.
The location is great! There is a lot around the apartment for you to do. Everything is pretty much in walking distance... from main attractions like Ponte Vecchio (~7 min walk) to a grocery store to THE BEST PIZZA AROUND! (Gusta Pizza!). Piazza Santo Spirito is full of nightlife with bars and restaurants all right there for you. With that being said, 2 of the bedrooms are facing the square so its pretty loud at night up until 2am.
There are a few flights of stairs to get to the apartment that are very hard on your feet and the key to get into the apartment is tricky to open but once inside, I felt secure at night with all the locks on the door. Heat and hot water works very well, though only one person can shower at one time which isn't a problem just should note otherwise you'll both be taking cold showers!
All in all- the apartment was perfect to stay in! Rooms are huge, Federico responds very quickly to messages and the apartment if very much a Florence/Renaissance feel!