We had a group of three staying at Giulia's place. The apartment is nice and clean and looks like it does in the pictures. It was nice to have two bedrooms and two bathrooms. I think it's important to note that one bed is soft and the other is very firm. If the people in your group aren't used to a really hard bed, there may be problems sleeping. Also, the apartment has thin ceilings so we could hear the neighbors sometimes and also noise from outside. This is pretty normal when you are staying in a central location. The second bedroom isn't as close to the window is not as noisy.
Giulia is a wonderful host! Super communicative and responds to messages quickly. She sent us some Tuscan country side tours and also booked our tour once we had decided. We needed a taxi a couple of times while we were there and she scheduled them for us.
The location and neighborhood is nice. It's about a 20 minute walk from the train station and 15 minutes from the main market, Duomo, etc. Because we were only there for two days, we would have preferred to stay closer to the train station and markets since that is where we spent most of our time.
All in all, I would recommend this place for your stay in Florence!