Antonella's apartment was definitely in the heart of Florence. Within walking distance to the train station (20-25 minute walk), there are restaurants all around as close as a 2 minutes walk and the market is right around the corner. The Duomo is a short 10 min walk away and Pizzale Michelangelo is a 25-30 minute walk, definitely worth walking to, bring a bottle of wine, find a spot in the stairs and enjoy the sunset. Antonella and her husband were very accommodating letting us check in early so we didn't have to carry our luggage around town for hours. We would stay here again.
I know in previous reviews there was mention about it being loud on the weekends. There is a bar across from the apartment main entrance, it was louder during the weekend but not enough to keep us up or even any need for earplugs and I am a light sleeper.