We have just spent 5 days in Lorenzo's appartement and everything was perfect. We came with our 2 children and their both grandmothers and each one could have his own room and his intimity. The flat is perfect, very well located, only 10 minutes by foot from the Ponte vecchio. Just arround the flat there are a lot of places to eat or to by things for cooking at home.
Lorenzo was not here to welcome us, his co-host Marco was, he was always available to answer our questions, and managed to book us various taxis. He was very friendly and sympathical. The street might be sometimes a bit nosy, but never mind, I will highly recommand this flat to anyone who wants to stay in Florence.