We *loved* this apartment. Annalisa was very accommodating when our train was delayed and sent us detailed instructions and pictures for checking in without meeting her.
The location is perfect with many bars and restaurants nearby. We had a steak at Trattoria Vechio Mercato that was to die for, as well as many other meals and drinks nearby. The stairs are no joke though and I would not recommend this spot for anyone with mobility issues, or even super large luggage.
The apartment itself is great. High end finishes, comfortable bed, and nice sized shower. We had no issues with street noise (only construction noise from the next building over); in fact, our only tip is "don't sleep with the shutters closed!" Between the nice bed, the darkness in the room and whir of the air conditioning... We way overslept one day!
I would love to book this place, if back in Florence again.