My friend and I (females in our 60s) are just home from ten days in the apartment, and it was perfect for us. We spent time every day admiring and photographing the beautiful view. Alessandro met us upon arrival and introduced us to the workings of the apartment. He also offered to arrange a driver for a day trip, which we decided to use.
We were only given linens for one bed, and it was suggested that we share the one in the bedroom, which Americans would call a queen size. Though it seemed a little weird at first, in truth both of us wanted the bedroom with the view, so we did it, and it was fine.
We made good use of the nearby upscale supermarket, but keep in mind, there is no oven in the kitchen. Otherwise, the kitchen was very handy and modern.
The hot water was capricious, and more off than on, and the shower drain was very slow, so the shower could easily overflow while running the hot water to see if there was any that day.
Still- we loved the place and the location. It was indeed very safe, there was gelato downstairs (!), and it is very close to all the museums and many nice restaurants in Florence.
We didn't hear from Alessandro or Luca during our stay, but since their office was in the same building, it was easy to reach them when we had questions.
All in all, a very positive experience, and we would definitely stay here again. (As others have noted, those stairs....I'm sure they're at least five stories up!)