The location is everything - you can walk everywhere, and really get a true feel for Florence!
2 of us stayed in this apartment for 2 days, and it was plenty big enough so that we did not feel cramped. A word of warning though - since this is an older building, the bathroom is very small, specifically the shower. My 6'5" husband was unable to turn around completely in the shower, and for a woman, it's difficult to shave your legs! But if you're staying for a short while or you are shorter than 6'5", it's definitely manageable.
We were VERY grateful for a small elevator/lift as most Italian apartments don't have one!
The hosts were VERY accommodating and stayed in contact with us, giving great recommendations about the city.
All in all, we would love staying here again, since the proximity to everything and quietness are a rare combination that works well!