I was in Florence with my daughter for three weeks while she was working at a university project and we loved staying at Elena's apartment. At all times Elena was reachable and in contact with us. From the first moment she made us feel welcomed; she was waiting for us with a bottle of prosecco, Nutella and marmalade. We even had an unfortunate incident with the entrance's lock: the second night we went out for gelato (of course) around 10:00 pm and when we put the key into the lock to open the door the key broke in half. We called Elena who immediately came to our rescue even though she lives and hour and half from the center of Florence. She almost had to almost break the door and we made to the apartment almost at midnight but the next day she was contacting us to tell us the administrator would fix the lock and she made sure we had a key immediately.
Regarding the location it just couldn't be more perfect. We could see the Accademia from our window, the Duomo was two blocks away and the gelateria next door was perfect. There was a small Carrefour supermarket a block from the Accademia where we bought some snacks to have at the apartment. Even though we didn't do any cooking the apartment had everything we could have needed. Another great advantage was the Accademia Bookstore (right across the Accademia) where you can buy reservation tickets to any museum in Florence to have preferred entrance.
The A/C worked to the point that some nights we had to turn them off even though all Italy was in the middle of a heat wave - there is one A/C in the master bedroom and a second one in the living room. The bathroom was spacious and modern, having a shower instead of a tub was certainly a plus. The washing machine was certainly something we used a few times.
I would recommend Elena's apartment to anyone: the room distribution is excellent ans spacious, the location in the center of Florence couldn't be better and Elena was certainly a perfect host.
Will certainly stay at the apartment next time we visit Florence.