My friend and I spent six nights at Vieri e Benedetta’s.
The location of Oltrarno is wonderful: right by Piazza Santo Spirito and nearby many restaurants and bars. It’s also removed from the super-touristy sites!
The reviews are correct about the stairs - it’s quite a hike up the four floors, especially with luggage!
Our only complaint - and it’s a really small one - is the kitchen. Because we were there six nights/seven days, we did wish to eat breakfast and make at least one dinner at the airbnb, but the kitchen was not super well-equipped. You have to really work with what you’ve got!
Grazie Vieri e Benedetta!