We stayed at Modestino's place on Via Della Chiesa for five days. It was great. His associate Rita was there to greet us.
The plumbing worked well, there was plenty of water pressure, the garage was spacious by Italian standards, (although I did have to recruit a passerby to get our car from the narrow street through the narrow entry the first time, after that I was able to do it myself.) The rooms were spacious, the fridge kept things cold and the freezer froze. All things you can't take for granted when travelling. There were even two (!) ceiling air conditioners that worked.
The apartment was very convenient. Local favorites were a coffee and wine shop you reach by turning right out the door then the first right. It is the first place on the right with seats on the sidewalk. Lots of regular customers there, a real people-watching place. There is a great restaurant called I' Brindellone a few minutes away that was amazing. We found it by looking for nearby restaurants on Trip Advisor. It was likely our best meal in Florence, and it was 70 euros for three including a good bottle of chianti. Enjoy your stay.