I have never used airbnb before and was at first skeptical about the whole thing but after my trip to Italy this past May, I am definitely a believer.
I traveled with a family of four and this place was just perfect for us.
This is a newly renovated apartment with a great location. It is located one street over from the ponte vecchio (2 min walk) and is right beside many restaurants and shops. There is a post office beside the apartment, a grocery store 2 min away, a laundromat 2 min away and is about a 10 min walk to the duomo.
The apartment was very clean, nicely decorated and stocked with kitchen supplies should you want to cook. We didn't because we ended eating out during our stay there.
The hosts were very welcoming, friendly and hospitable. They even had water bottles for us in the fridge and coffee and tea if we wanted.
Overall, we had an amazing stay and would definitely stay there again if we go back to Florence.

Tip: it is about a 15-20 min walk from Firenze Santa Maria Novella train station. If travelling with luggage, more advisable to taxi. If the taxi driver does not know the address, a good landmark is the Piti Palace Hotel. The apartment is on the same street as the hotel. Taxi is about 10-15 euros.
Also, no wifi at the apartment but there is supposedly an internet place, one street over according to our hosts. We couldn't find it however, but we also didn't look for it seriously.