Staying at Mario's was a great experience. I choose airbnb not just for the price but also to experience the Italian culture with an italian family.
Mario and his wife were very welcoming and warm. They had little snacks, coffee, tea, city maps, dictionary.... everything one needs to feel comfortable. The room is big and has a comfy bed. It is in a great location too, not too far from The train station.
Every time i needed directions he was very eager to help, giving me suggestions and his opinion. I loved staying there, just please take mosquito repellent.
Oh, also make sure you pack light, i had 2 suitcases, and he lives on the 4th floor and there is no elevator!
If i ever go back to Florence, ill definitely go back!