Literally right next to the big Florence Duomo Cathedral, the experience to live in a historic 500 year old building is amazing, Florence is an amazing city and this is the best located flat to best experience Florence I was amazed.
I recommend the "Inferno Tom Hanks" guided tour at Palazzio Vecchio, the evening private guided tour of Florence with Luca (from Airbnb Experiences) and if possible a good guide at the Accademia Museum to see Michelangelo's David too, whatever you do, book about a week in advance your skip the line guided tours and queue skipping tickets online a B Ticket. Booking such skip the line tickets on the day or the day before doesn't seem to be possible at cheap. But if you book a week ahead on B Ticket you should be fine for just I think a 4euro to skip the line or/and for a guided tour.
Get the Bollito sandwich at the sandwich store right outside the flat on the street, it's truly amazing. I miss that sandwich.