Stefano (who's name is actually Scott from Canada) is a nice guy. He communicates fast en is helpful. The accommodation is impressive, the photo's gives you a real good impression. The 'Inferno' room will stay in my memory forever.
For me it was the first time a booked with airbnb. Unfortunately I didn't read the description well.. there was a dog in the apartment. My girlfriend is allergic for dogs, so we have to leave earlier (no refund). I think it is also good to know that there is little privacy in my opinion. Of course you have your own room and your own bathroom (which is basic), but for example; you reach the bathroom through the main (shared) corridor.
The location of the apartment is perfect, you stay in the center of the center of Florence. From Scott we received a good tip for dinner to eat the 'steak Florentine'. I forgot the name of the restaurant but you should definitely go there if you like meat, best steak ever!